RPi4 + Mate + Google Meet

Howdy - I setup a number of Pi4 and TV combos at a local preschool so they can conduct video lessons together. Everything works fine except when the Google Meet meeting ends the RPI4 freezes or gets to a state where the mouse barely moves. Running Firefox but I have also tried with Chrome to no avail.

Anyone else run into this?

I'd like to know the answer to this as well as I've got a similar problem. I'm using a Raspberry Pi 4 8 gig running Ubuntu Mate and the only thing that doesn't work right is the use of Google Meet. The webcam shows my image and video but then it locks up the browser just about every time. Any thoughts? Thanks.