we have exactly the same problems since Friday evening. Problems started around 6 p.m. CET (shared screen flickering, audio dropouts and delays, connection dropouts). We managed to hold the meeting of 15 participants until the end shortly after 7 p.m.
Today (Monday) we had to cancel the meeting because the problems were too serious and we did not hear the instructor. As we found out when there were only two of us in the room, everything was O.K., but even one more participant made the session unusable. In the group of 15 participants, less than half were connected, the others kept loosing their connection.
We also noticed some changes in the GUI that led us to the idea that a new version of the client was released - maybe this is the root of the problem.