I have a problem with missing layers when printing with tpu filament. The problem always starts on the upper half of the print. (Image)
Bambu A1, TPU A90, Generic TPU preset.
Let’s see the print preview window also…If it is indeed layers missing, it will preview as missing layers…
I also have this problem. It seems to be the same layers in every print. The only think I can think of is the filament stretching, the filament reel not turning, and then all of a sudden catching up. I found it was worse when inside filament drier (which has bearings) and is a little better in bearing roller mounted on side of the printer. I read some print profiles have found pulling a section of the filament off the reel so it is hanging loose may solve this problem.
As you wrote, i only had a problem with a 1kg spool. With the smaller 250g spool everything was fine.