Huben Huben GK1 magazine play

Hi everyone. I had to disassemble my GK1 and now the magazine can be slightly rotated half a chamber back and forth when it's locked. The gun shoots so it's not really an issue but before it was rock solid when the lever was pushed in. I want it to operate perfectly as it was. Can anyone tell me why it is like that now? Thanks
 
I've checked it and everything looks ok. After reassemble it was still the same. But there are no malfunctions or safety issues. It's been fired a lot. I must correct myself of how I described the play of the magazine. When it's locked it's not moving in CW direction only a little bit CCW.
Mine has been like that from day one. A few mm of play in the ccw direction.