User having no audio/video

Hello there,

I have the following issue with a regularly occurring Jitsi Meet instance, and a specific user. Up to now, this has worked (depending on network reliability) more or less well for all of the users, but since yesterday, one user - who was regularly joining in the past - experienced an issue I haven’t seen before.
The user was/is able to join, and everone else sees and hers the person, but the user cannot hear or see anyone else. She is saying that she sees the small tiles for all other participants, but each of them bears a crossed out microphone and camera, and there is no possibility for her to activate incoming video/audio.

She’s using the same PC and browser (Chrome) as before. I wasn’t able to find anything trough the search function, so please bear with me. Any help is appreciated.

kind regards, christian.

Ah yes, sorry - in case the question comes up, this is happening on a self-hosted Jitsi Meet instance; but also there was no change recently.
Both server and user’s computer were restarted, but to no avail.