Mail in Catalina sometimes tries to Open junk emails instead of Deleting them

Recently in Mail on OSX Catalina on my MBPro, when I select all 100+ emails in the Junk folder and hit the Delete key or click on the Trash icon, I get a pop-up asking me if I want to OPEN all 100+ emails instead of the usual pop-up verifiying if I want to Delete them. Fine if I notice in time, but several times now I've ended up with a ton of open emails all over my screen! Annoying little glitch.