Expanded thread collapses when first message opened.
If I have a USENET thread expanded and open the first displayed message, the thread then sucks back up and has to be expanded again, then continues as expected.
If I have a USENET thread expanded and open the first displayed message, the thread then sucks back up and has to be expanded again, then continues as expected.
Wšě wotmołwy (1)
This is a known problem, but the existing bug doesn't receive much love. You may want to vote for it. https://bugzilla.mozilla.org/show_bug.cgi?id=1526765