Continuous disconnection

my son’s teachers are using jitsi meet for video lessons (21 students class) but for us it’s impossible to follow because we are continuously “kicked-out” of the room, back to the screen where you enter the password to access the meeting.
Each ‘session’ is very short, often less than one minute…

We tried to join both via browser and via app, via iMac, iPad, Windows laptop and Android mobile. Always the same problem.

We doubt it might be a connection (e.g. wifi) problem, since we are using several other platforms without any problem…

May anyone help?
Thank you!!