Bambu A1 Mini network timeout

[chijb55]

I submitted a ticket for this previously. Bambu reported that it must be a network configuration issue - although nothing else lost connection - and closed the ticket.

I’ve done everything they asked.

I split my WiFi network into isolated 2.4/5 channels, and moved Bambu to the 2.4.

I did a full factory reset.

I reinstalled the previous s/w version.

NOTHING.

Device times out when printing. And it takes FOREVER to even find my printer.

The Bambu sits on a shelf next to a low-cost Epson printer that has never lost connection to the network once. Finds it, sends/receives updates, prints without an issue.

This is not my local network’s problem. But Bambu seems to be hanging me out to dry with a printer I can’t use the way it’s supposed to work.

Really regretting this purchase right now.

[lion7718]

1: Have you checked your Firewall settings..??

2: Is the Network Plugin installed in BS or Orca..??

[chijb55]

Yes to Firewall check. All ports open. Network Plugin is BS. Worked fine for a year. Now it refuses to print and times out.

[user_1563201763]

The same issue (a1 mini)

no answer yet for icmp_seq=696
no answer yet for icmp_seq=697
From 192.168.1.12 icmp_seq=696 Destination Host Unreachable
From 192.168.1.12 icmp_seq=697 Destination Host Unreachable
From 192.168.1.12 icmp_seq=698 Destination Host Unreachable
no answer yet for icmp_seq=698
no answer yet for icmp_seq=699
no answer yet for icmp_seq=700
no answer yet for icmp_seq=701
From 192.168.1.12 icmp_seq=699 Destination Host Unreachable
From 192.168.1.12 icmp_seq=700 Destination Host Unreachable
From 192.168.1.12 icmp_seq=701 Destination Host Unreachable
no answer yet for icmp_seq=702
no answer yet for icmp_seq=703
no answer yet for icmp_seq=704
From 192.168.1.12 icmp_seq=702 Destination Host Unreachable
From 192.168.1.12 icmp_seq=703 Destination Host Unreachable
From 192.168.1.12 icmp_seq=704 Destination Host Unreachable
From 192.168.1.12 icmp_seq=705 Destination Host Unreachable
no answer yet for icmp_seq=705
no answer yet for icmp_seq=706
no answer yet for icmp_seq=707
no answer yet for icmp_seq=708
no answer yet for icmp_seq=709
no answer yet for icmp_seq=710
no answer yet for icmp_seq=711
no answer yet for icmp_seq=712

[user_1563201763]

So, the printer can work perfectly for days or even weeks, then suddenly disappears from the network. Bambu Studio can’t find it, and ICMP starts showing either very high latency or complete packet loss.

Typical behavior looks like this:

Request timeout
Request timeout
785 ms
62 ms
837 ms
Request timeout

To understand what was happening, I wrote a monitoring script that automatically captures diagnostics whenever the printer becomes unreachable.

During every failure it records:

Linux ARP/neighbour table (ip neigh)
MikroTik wireless registration table
MikroTik ARP table
wireless log entries
state immediately after recovery

What I found

The failures are not always identical.

In some cases:

the printer completely disappears from the wireless registration table;
Linux reports the neighbour state as INCOMPLETE;
the router ARP entry becomes stale.

In other cases:

the printer is still present in the wireless registration table;
ARP is still valid (reachable or delay);
but the printer does not answer ping.

The MikroTik logs repeatedly contain messages like:

unicast key exchange timeout

Earlier I also observed:

group key exchange timeout

After that, the printer associates again.

What is NOT happening

The problem does not appear to be caused by:

DHCP
IP address conflicts
poor signal strength

The printer has a stable signal (around -65 dBm), and every other Wi-Fi device in my house works normally:

multiple IP cameras, several smartphones, laptops, desktop PCs. Only the A1 Mini exhibits this behavior.

Current experiment

As a test, I changed one MikroTik setting:

/interface wireless set wlan1 adaptive-noise-immunity=none

I also increased:

/interface wireless set wlan1 disconnect-timeout=15s

After making these changes, the printer came back online and has remained connected so far.

However, I cannot say that this solved the issue.

This problem is extremely difficult to validate because it occurs very rarely — typically only once every several months. In the past, the printer has also recovered after a simple power cycle without any changes to the router configuration.

For that reason, I cannot claim that adaptive-noise-immunity=none is a fix. At this point it is only a documented observation that may help others investigate similar issues.

If anyone else is using an A1 Mini with a MikroTik access point and has seen unicast key exchange timeout or group key exchange timeout messages in their AP logs, I’d be interested to know whether you’ve found the same behavior or a different root cause.

[RetroSharky]

@user_1563201763

…

Have you ever tried switching channels on the 2.4 GHz band?

Maybe some of them are overloaded - for example, due to neighbors or interference. You could start by scanning to see what’s going on on your channels, and then switch to one that’s stable.

That would also explain the randomness, because depending on which channel your router connects to and causes problems, it might kick some devices off, but not all of them. Here’s a picture of what it looks like. For example, I’m currently using Channel 7 because it has the lowest traffic at this time of day.

---

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In particular, your “adaptive-noise-immunity=none” fix also suggests that a channel in your area might be overloaded or interfered with - for example, by a neighbor.

Try scanning your surroundings for channels 1–13 on the 2.4 GHz band, and note the time as well - the interference might not always be present. In fact, cases like yours are often caused by a neighbor’s rather than a router or network problem, and they don’t necessarily affect all devices - often just the weakest ones, and unfortunately, Bambu doesn’t use powerful antennas.

You could try setting a specific channel - a different one every day - and see if that solves the problem.

---

Beside: The most important thing is what OP has already done, but I didn’t see it in your post or must have overlooked it: Use unique SSID names for both the 5 GHz and 2.4 GHz bands. Otherwise, this always causes problems if the networks aren’t separated.

Also, don’t use a name that a neighbor is already using!

[user_1563201763]

I live in a detached house in a low-density residential area. There is very little Wi-Fi congestion here, I can only see two neighboring Wi-Fi networks.

I also checked the channel allocation and selected the least congested channel available.

Additionally, I intentionally prevented the printer from connecting to the 5 GHz radio, so it always uses the dedicated 2.4 GHz network. This was done to maximize signal quality and eliminate any possibility of band steering or roaming between 2.4 GHz and 5 GHz.

At the printer’s location, the signal strength is around -65 dBm, so poor RF conditions do not appear to be the cause of the issue.

[Bullocks]

@user_1563201763

Typical behavior looks like this:

Request timeout
Request timeout
785 ms
62 ms
837 ms
Request timeout

If that is source:yourPc dest:printer, I’d diagnose that as a poor wifi connection. You might have better luck setting up a uniquely named SSID clamped on only 2.4ghz if you haven’t already, that greatly improved my printers stability.

[user_1563201763]

The printer is located next to two smartphones, two laptops, and a desktop PC. There is also a Wi-Fi security camera even farther away, near the corner of the house. All of these devices are in roughly the same direction from the access point, and all of them have stable Wi-Fi connections. The A1 Mini is the only device that exhibits this behavior.

Also, this doesn’t appear to be an isolated case. There are multiple reports from other A1 Mini owners describing very similar Wi-Fi issues on Reddit and on the Bambu Lab forum.

[RetroSharky]

This is by no means a blanket recommendation, but rather an additional note. This suggestion is only for people who are having trouble maintaining the signal.

---

Contacting support and having them send a new antenna. Even if the warranty has expired, the parts are pretty cheap. Maybe the cable just isn’t fully plugged into the circuit board properly anymore. The printer vibrates constantly, so it’s not surprising that a cable might come slightly loose.

---

or, get an adapter cable and install a decent antenna.

[Bullocks]

You didnt answer the unknown, are all those tests you listed " source:yourPc dest:printer,"?

Do you use any repeaters in your setup? If you have VLANs enabled, Are they on the same VLAN according to your networking devices?

[user_1563201763]

All devices are on the same subnet. There are no repeaters, mesh nodes, or VLANs involved.

MikroTik AP/router 192.168.1.1
Android phone (Bambu Handy) 192.168.1.2
Bambu A1 Mini 192.168.1.3
Laptop 192.168.1.12

During the failures, the printer was unreachable not only from my laptop, but also from the Android phone running Bambu Handy. The app could not see or connect to the printer either.

[Bullocks]

Yep then I’d open a ticket. They’ll probably send you a new antenna/module/mobo, i dont have the mini flavor and don’t know the specifics. Since thats the likely route [IMO], it’s maybe a fun time to crack it open and see if replugging/reseating the antenna/board fixes the issue.