Just sharing an update in my similar case - they’re sending a replacement heatbed unit. Hopefully @ebert_coetzer will let you know if this works out resolving my issue as it could be related.
So I have a good update. I initially replaced the hot end and heater assembly which Bambu sent me as part of my ticket. this did not resolve the issue. Bambulab then sent me an extruder and it seems to have done the trick. I have no scraping sounds when using the hardened steel nozzle and the print comes out as nice as expected with these machines.
Thank you all for your participation and suggestions in this thread. You are the reason this community is as great as it is. Hopefully this thread will help others diagnose and rectify a similar issue.
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I’m on deck to receive a new hotend. If that doesn’t work, maybe I’ll see an extruder next. 
We’ll see. Either way - good to see your issue is resolved. 
they can resolve mine now.
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Just sharing the update - Support fixed my issue finally now too. The replacement hotend did the trick for me. Comparison photos of the new first layer now compared with previous. First layer looks just about perfect now.
Brilliant, this makes me believe that the hotends have some minor differences geometrically which you would not really expect to be the case… Glad yours is fixed too. Bambulabs have some great support teams always happy and willing to assist.
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I have been having the same problems. My first layers look like sh*t and they stick way too hard to the plates. I contacted Bambu about it and hope they will also resolve this soon.
I have the same problem when 0.2mm stainless steel nozzle was used. The first layer was very thin and rough especially with smooth plate. Anyway, I figured a workaround that can be done with a couple Bambu Studio setting.
For the thin layer, you can compensate that with Quality -> initial layer height. Just add whatever the actual thickness that is off from the desired. For example, if the layer height is 0.1mm and the actual first layer thickness is 0.07mm, then make the initial first layer to 0.13mm. This will restore the thickness back to 0.1mm.
Once changed, test print first layer again. If the layer is still rough, then adjust Quality -> initial layer flow ratio. The starting point is relative to the initial layer height compensation. For example, if you need to compensate initial layer height by 0.03mm to get 0.1mm layer, then it is 0.1 / 0.13 = ~0.77, which is the initial layer flow ratio. Why? printer extrusion of first layer is for 0.13mm thickness, but we will only get 0.1mm. This means printer should only extrude 77% of filament for 0.13mm layer in order to get 0.1mm layer.
To Bambu Lap … please fix the issue in the next Bambu Studio release. It should be a simple fix. Likely just some gcode update.
I’m being very confused about what’s happening with my A1.
Worked fine when I got it. Then for a period of time it was printing, but needed an offset of 0.14. (I created a custom print that would print a number of test squares all with different Z offsets.)
We tried tightening the hot and screws which did not work, then they sent me a new hot end which to my surprise fixed the issue.
Two weeks later, and now it’s printing slightly too high.
Of course printing a test with a negative Z offset is a lot trickier.
Test with 0 offset
Any idea WTF is going on?
I’ve had this issue with 2 of my A1’s. They sent the hotend assembly kit. This resolved the issue with one of them. Hotend Heating Assembly - A1 Series
I’m not battling for them to replace on the other printer with the exact same issue, first layer is suddenly way too close. I believe this part has a strain gauge in which if misreading will provide an incorrect Z offset.
As time goes on I expect this to become a very common problem with the A1’s.
In most instances it appears that they have an issue producing hot ends with the exact same dimensions. Ask them for a new hot end, it will 99.9% of the time fix the issue I think.
For me a replacement hotend fixed the issue for 2-3 weeks, but now the offset is quite wrong but in the opposite direction.
If you do figure out the offset you need, G29.1 ± OffsetNumber in your gcode will work.
I’ve had a 2nd A1 need a new hotend assembly. It fixed the issue. Im not sure why it fixes the issue though when I look at the parts it contains. The nozzle isn’t part of it and in my case changing the nozzle made no difference
It already been -0.03 for a textured pei plate? strange now it seem to be -0.02…
Some bed have uneven surface and it look like its my case. At first i though it was Z offset because i had low underextrusion in the same area between first layer print tests so what i did is set layer height to 0.25 and set bottom flow to 1.035 (after a filament flow calibration). Look like its working fine now… no more underextrusion.