How does the air buble keycaps look like? Can you post a photo of it?
I have 3 duckies: DK9008 Shine 2, PBT dye sublimated G2 Pro DK9008, Shine 3 DK9008 Snake, except a few minor issue, all are fine
One filco, which came with broken keycap on key 'k' and loud squeeky backspace.
One poker2, which is fine.
One leopold fc660c, which is also fine.
Well, no need for me to say which one has bad QC ...