I have an Alien 5" KISS fc.

When I activate level mode, the quad has a deliberate drift to the right and forward.

When in acro mode, full throttle punch shows very little drift on either axis, honestly, it could be the slight breeze when in acro, it is not worth adjusting the I gain in my opinion.

I think the accelerometer is disabled in acro mode, and I can't remember if I did the " calibrate accelerometer " function with acro or level mode active or if it even makes a difference.

I like the way the quad flies in acro, I only use level mode if I want to let someone hover my quad, but I am a little baffled.

Danny

I think you answered your question. Make sure you have your accelorometer on and that its calibrated. I've also noticed that it helps to have your quad level when you arm it if your in level mode.

Hovering is overrated...........

I don't remember if kiss has an option to trim the acc... If not, you could try to calibrate it again slightly tilted to the back left?

PS: but i'll also add that on kiss fc i always had a hard time setting transmitter center just right - if it was off a little bit (say in your case 1502 instead of 1500-1501) this might be more noticeable in level mode...