@DelphineM Firefox seems to lack some WebRTC features. The side-effect seems to be that there are performance issues on all participants when at least one is using Firefox.
Here is for example an article in French: https://linuxfr.org/users/space_e_man/journaux/jitsi-denigre-firefox-et-decredibilise-des-logiciels-libres
Welcome to Qowala's Mastodon instance!
Here, we love open source and we study and work on social networks so naturally we also host a Mastodon instance.
Friendly people are welcome, but as this is a small server, there are limited available slots. So, choose wisely to join or not.