Yeah, not e2e encrypted when it goes through videobridge (as per this article).

I haven't checked, but its possible for 1-to-1 or small meetings they may go full mesh, which would be e2e encrypted - a few platforms do this.

edit: just checked and jitsi is "full mesh" for 2 participants - if you have 3 or more (video) participants, it switches over to SFU.