Some wikipedians on fr: are reporting a bug (https://fr.wikipedia.org/wiki/Wikip%C3%A9dia:Le_Bistro/28_octobre_2020#Bug_(Ubuntu_et_Firefox_%C3%A0_jour)?)
When I try to edit a page, during a few seconds, the mouse cursor is doesn't work correctly.
For example, if I try to edit this table with the visual editor. During a few seconds, if I click on a cell, a different cell will be selected. After a few seconds, everything is working as usual.
https://fr.wikipedia.org/wiki/Utilisateur:Pyb#Imports_de_donn%C3%A9es_ou_fonds_photo
I'm using Windows + Firefox 82.0.1