https://bugs.winehq.org/show_bug.cgi?id=51442
--- Comment #17 from Roman Pišl rpisl@seznam.cz --- This bug can be triggered quite reliably without hitting other bugs with:
firefox.exe -private -devtools https://www.phoronix.com
It is very likely that at least one connection remains stalled a no other content can be downloaded since then.
I'm also working on a simple and reliable example to reproduce the bug but without success so far.