Seestar Drizzlex2 grid patterns Problem

Dear Siril creators,

I have tried the new Drizzlex2 script for Seestar. It was done on over 2000 subs of 10 seconds in alt-az mode. On the live stacking saved FIT files.

Unfortunately I get strange geometrical patterns in the background, like a grid that rotates. Color balance is also different.

Am I doing something wrong ?

Thank you for any help,
Stevan