Opening local files leads to infinite refresh loop

This seems to be a regression introduced in 10.0.x based on esr78 (I have only tested Tor Browser 10.0a6 on a x86_64 Debian Sid system):

If I open some local file, e.g. just an empty .txt, the file is opened and loaded but keeps on refreshing like crazy, like if you keep the F5 key pressed in, almost utilizing two full cores. HTML does not seem to get enough time to render at all. If I keep the ESC key pressed for a while it seems to stop, but this also stops HTML rendering, so it is not really an acceptable workaround.