Invasive icon pops up

First post, so apologies if I transgress any conventions. I will try to comply with all regs as I become familiar with them.
So I'm a newbie with Mate... just installed 20.04 on a cheap Lenovo laptop. This laptop had lots of quirks with another distro, but seemed to be fine with Mate, until just now.
I searched the forum, and could not find anything related to my problem.
An icon appears on the screen while I'm typing or browsing. It's like a sound volume icon... i.e. a speaker with "sound waves" emanating from it. It's about 1" square (2cm x 2cm). I cannot delete it.
When it pops up the keyboard is disabled. The mouse pointer will point, but cannot click on anything on the desktop. I can click on the menu to shut down the system... which is what I do.
I know this is a quirky problem... and I suspect it might be something to do with the laptop's hardware. But it is a bother because I can't even save text when it pops up. Just have to shut down an lose the work.
If I should post any cli readouts here could some simple instructions be recommended?