I can confirm that you are right. What made me think it might have been related was how sudden it was, and the fact that it happen immediately after the firmware update. It seems I was fooled by a coincidence. I found that I had a spare nozzle, I salvaged the assembly from the sus item and rebuilt a whole hot end. I’ve completed several proper prints since, so I think I’ll be good.
Still, I am glad I could learn much thanks to you and Eric.
Its not wet filament, its not your hot end, its not your extruder. Its the software! Double check your settings especially printer type / nozzle size.
I have found that the new software defaults to a 0.2 nozzle. Of course you can not see it unless you hover on the printer type. Check your connected printer in Studio and adjust as needed.
I fought my X1C for two weeks and had tech support helping, to no avail.
Finally after looking at settings for hours I hovered over the printer and found the correct printer with an incorrect nozzle setting. This setting will supercede the nozzle size in the software. Again check your printer in Bambu Studio!
You “had” to do nothing, you chose to do so.
danno, you make an interesting point, and it could very well have been that, in theory. Only it happens that when I upgraded the firmware and BS to the latest in the first place, I did check for that and made sure that it was indeed my X1C with a 0.4 nozzle. I wasn’t too sure about what previous information would be retained from my previous configuration and that made me a bit paranoid about it.
Now, the nozzle I replaced was my initial nozzle, the one that came with the printer (I print small volumes, as I am not often there). As soon as swapped if for a shiny new one, everything was tickty-boo.
I’ll heed your advice though, for the next time when BL will throw a software version and/or a firmware at us. Thanks for that tip 
ProtoSpyre: I won’t argue with you over semantics. Implicitly, when a new firmware comes out, it’s supposed to be some sort of upgrade or improvement. One cannot postpone for ages. Had I done that, over and over, at some point something was bound to go wrong and there would have been someone, maybe even you, who’d give me a snarky “You chose not to update, it’s on you”. So in essence, yes, we are in control of our choices but we can’t always know the consequences in advance. If anyone’s got that kind of cheatcode for life, they can take my money 
Glad that you can fix this, cheers!
having this EXACT issue. printed the same model several times without a fault. Upgraded firmware and software and now 100% failure. Spaghetti every single time. How can I roll back the firmware?
Please look at my reply above. Hope you fix it!
I managed to resolve it by downgrading firmware through the handy app, I wish i didn’t have to use an app for this and could keep copies of firmware on my desktop PC but at least my printer is printing properly again. I think there is an issue with the latest fw because that’s all that changed
You can download (and save) the 01.08.02.00 version (2024/08/12) that can be installed offline. Download
A very valid point I’ve had the same issue with the software update!!