u/Inflation9161

i have just stacked around 1600 frames of IC434 in siril, and it make this weird blue rectangle thingy around the main part of the nebula, it completly ruins me trying to pre-process it in astrowizard, how do i fix this? i do not wanna crop the image that much

Notes: i use a seestar s30 pro and used the seestar pre processing script in siril