My panel extension was placed in “changes requested” because supposedly it didn’t work. Reviewer comments stated: “Blank panel, spammed a POST endlessly with a 429 error.” I immediately went to my channel page and - lo and behold - the extension would not load into the page. However, there were no 429 errors. Instead, I was getting 404s as described in this topic: https://discuss.dev.twitch.tv/t/solved-404-the-specified-key-does-not-exist/11921. I was getting the same 404 and nothing loading on the config page.
However, I knew that my uploaded assets were all in the root directory. So, the cause of my 404s couldn’t be the same thing. In the dev panel, I returned my extension to the “testing” state and then immediately moved it back to a hosted test without changing anything else. All of a sudden, it was working again. No more 404s. Everything working as expected.
I’m inclined to simply resubmit for review again and chalk this up to bugs in the submission process. Not sure what else I can do.