It seems like this bug reappeared.
I didn’t download any new extensions. I’m not experiencing any internet connection problems either. Everything was fine until today.
I found the reason that’s causing mine! It’s one of the extension that I have called “Pixiv Toolkit Next” which I’d had for a pretty long time. Disabling it fix the problem for me.
So it’s quite possibly caused by one of your extensions, I suggest disabling all of them and turn them back on one by one to see which extension is causing this issue.
@Username_Haoto,
You stated that you didn’t download any new extensions, but that does not mean that an old/previously installed one isn’t the source of the issue. I would test removing your extensions temporarily to check and see if one of them was causing the issue.