Curious/Interesting.... I always assumed clicking on the trash icon and rebooting simply but effectively uninstalled the module. But it's also why I stated that you should remove each module and reboot after each time....*very important the rebooting
I think the problem may have been that although I tapped on remove (and it got crossed out), when I rebooted, I immediately flashed the stock image. I didn't let it reboot with Magisk intact to fully remove the module's changes. Could that be the problem? Then when I finally flashed Magisk again, it was able to remove the module after a (second) reboot. WEIRD. If anyone knows about how this works. Please chime in!
On another note, I've taken a careful look at that module and the one I flashed was modified further by a random user, not the OP. My mistake, I didn't check what was inside. It had pretty much completely removed any throttling up to 95c lol. I don't know how it ran fine for a few days and became a problem once I rebooted last night. I have now carefully modified the thermal mod myself, and am testing it now. I will be posting it in that thread.