I have an SBIG ST-8300M used in conjunction with System Generator Pro ver 22.214.171.124.
When I am beginning an evenings imaging, for the first 1-2 hours, cooling is highly unstable. It frequently stops cooling, and, on occasions, even Warms Up. I have tried all sorts of combination between configuring cooling in the Camera tab and cooling using the Temperature window. I have struggled with this for a couple of years now, over several upgrades of SGP. Once the imaging is well underway, the cooling stabilizes and it maintains temperature with no issues. I cannot tell anything different about the situation as it stabilizes other than time has passed.
Based on some previous recommendations, I upgraded the power source to the SBIG to, now, 6amps. That upgrade made no difference. I have swapped out all cables a couple times. Nothing seems to help.