as stated in [#12986] users are unable to select list items from single select input controls in Firefox post version 78.5 (ESR)
if controls shown on page start (not as popup)
I can work around the issue by zooming out a bit in the Firefox window, perhaps there is a clue there. I find this necessary for configuring scheduled reports.
Also, I will get the same problem with popup controls with certain Application Themes applied.
System: Fedora 33, KDE Plasma desktop. Firefox 85.
I have the same problem with JSR7.8.0 and Firefox 86.
DropdownList is closing immediately when trying to select an item .
I've no workaround, neither the mentioned css or popupselect or zooming out.
I have the same problem with firefox 85.0.2.
The workaround of setting control display mode to pop-up and zooming out works for me, but I'm looking for better solution.
I have the same problems on Jasperserver 7.8 and Firefox 91.5.0esr.
No problem with Chrome
If i use pop-up display mode it works sometimes, but if you move the Dialog Box again DropdownList appear and close immediately.
Issue 12986 proposition in this issue solve the problem for me