I'm trying to track down a problem with copy/paste between Firefox and
other applications on Fedora 34.

I can copy in other applications and paste to Firefox, but not the other
way around.

[~](master)$ rpm -qf `which firefox`
firefox-93.0-2.fc34.x86_64
[~](master)$ rpm -qf `which gnome-terminal`
gnome-terminal-3.40.3-1.fc34.x86_64
[~](master)$ rpm -qf `which thunderbird`
thunderbird-91.1.0-1.fc34.x86_64

shift-ctrl-C in gnome-terminal, then ctrl-V in Firefox: works
shift-ctrl-C in gnome-terminal, then ctrl-V in Thunderbird: works

ctrl-C in Firefox, then ctrl-shift-V in gnome-terminal: does not work
(nothing is pasted)
ctrl-C in Firefox, then ctrl-V in Thunderbird: does not work (same)

ctrl-C in Thunderbird, then ctrl-V in Firefox: works
ctrl-C in Thunderbird, then shift-ctrl-V in gnome-terminal: works

Any suggestions or other things to try would be welcome, thank you.