When purchasing Amazon Prime video content, a 5 digit PIN display pops up:

Each of these digits is automatically replaced with a KeepassXC entry field using KeepasXC-Browser plugin on both Firefox and Edge Chromium. I was unable to find any way to enter the PIN or tell KeepassXC-Browser to not lock up those fields (e.g. using "redetect login fields" and attempting to skip the PIN fields). The only way I could get past this was to disable KeepassXC-Browser for Amazon. Since this is a widely used service, it seems that KeepasXC-Browser should know not to lock up those fields. Unfortunately, I don't have an easy way to test/replicate the problem since you have to attempt a purchase to get the PIN display but if you've recently authenticated it will skip the PIN request.