Unable to click in other programs without hitting CTRL + ALT + DEL

Hi,

I'm working on Windows 10 machines, and this has happened on more than one computer. I'll work in After Effects for a while and then will suddenly be unable to click on anything else. (For instance, I won't be able to navigate a Chrome window, etc). The only fix is hitting Ctrl + Alt + Del. Then things will work properly again. I've tried reinstalling After Effects and deleting my cache. Plus I tried a clean install just to make sure it wasn't a corrupt preference file. Nothing seems to work. I'm working in CC2019. Any help available?

Thanks!