In case the video doesn’t take you to the right spot immediately, going to ~7:49 (h:mm) (~7:48 for more context) should work.
He makes some matches, etc. at ~8:02, records the clip, finishes the match, then reboots a bit after 8:04.
I do maintain that it should be possible to close the overlay by clicking on the chat icon highlighted in the screenshot I took to ‘re-open’ chat, and then closing it per normal (as a workaround – obviously still a bug).
If in-battle, it’s in a different spot, obvs (top-left):
I haven’t had or noticed this for a while, or tried to reproduce it just yet; the circumstances around which it occurred do seem familiar, though.
Props to Teddy for taking the time to properly record, report and follow this up!!!