In the meantime, I have downgraded to the old firmware 1.04.02 because I had to calibrate a few new rolls of filament. The calibration now works as it did before the update. Although I really liked the new quiet volume, I think I’ll stick with the old firmware for now. I hope it’s not a big deal and they will fix it soon. 
Has anyone tried doing a factory reset with 1.5.0? I’m curious, but I read in another thread that doing so might lose the ability to do a firmware downgrade.
Interesting about the print quality. I actually made a print last night with some significant flat horizontal surfaces, and it suffered from severe under-extrusion. Even though this was with a fully calibrated filament that I’ve had no issues with previously.
I just found out that there is the option to revert to previous firmware version from the bambu handy app. Will definitely be doing this once the current print finishes. And I’ll be much more careful with installing new versions. The noise reduction was nice, but definitely not worth these issues.
I have the same issue, tested 3 times now after updating firmware today.
Also latest firmware and studio version (P1S)
I see this as well but when I click it, there’s “No content yet” which makes me think they took this away.
I opened a ticket today and already got feedback from Bambu Lab:
“…Our team is aware of this problem and working on solving it in a quick patch. …”
I backdated mine as well. I’ll wait until the “field” tests it before moving forward. The calibration issue isnt a killer but more of a annoyance.
Same issue here, downgraded back to 01.04.02
Same Issue here.Grey Button in Calibration.Latest Software and Firmware.
Updated to 01.05… yesterday and unless I’m referring to the wrong thing here, mine seems OK. Is this what everyone is referring to? All my options are green and seem to be calibrating fine.
It’s the Calibration tab that’s not working for me.
OK, so this isn’t just me. Your also seems off still on that last boat. Did you run another test with FW reverted?
I am also curious if anyone has tried Orca with the new FW to see if the Calibration tab is just broken in BS,
Yes. The calibration in Studio is different than the calibration you run from the printers interface.
The calibration selection at the top of Studio is for Flow Dynamics and Rate. The Calibration button you see when you are in Device view does the same calibration you do when at the printer.
Yes, you should calibrate filaments before use for better results. I even do it with Bambu filaments.
FYI…I looked here before upgrading to 1.05. Glad I did as I am in the process of calibrating some new filaments.
ah i understand now, i do run filament calibration for pressure advance using orca slicer, i just misunderstood, i thought there was some auto calibration voo doo going on from the calibration button in the device tab of bambu studio that i wasnt aware of for the P1 series similar to the lidar on the X1s but without lidar… oops.
I updated to 0.1.05.00.00 and the dynamic flow rate is grey after it’s done with the calibration process, gonna downgrade and will report back kings 
Same problem here, i did the 2 step manual calibration.
From the small calibration icon on the top.
Do the first step, put the new number and after do the second one and change according to the new value.
The benchy with the reset K value in the picture was printed with 01.04.02. The reason the “good” benchy in the picture isn’t perfect, is because I used the pre-sliced file that came with the printer and a non-bambu filament. This means that none of the prints in the picture were “flow rate” calibrated, only adjusted/estimated for K.
It works with Orca if you use the calibration drop down at the top left of the screen not the Calibration on the menu bar at the center of the screen.
