I've tested for this in Opera, and it does not happen there. But in Firefox, yes, it definitely happens, and apparently only with Evernote. So there is some kind of odd interaction going on between EN and FF.
I generally don't use FF for Evernote, so it would be helpful if others who have Premium subscriptions report this directly to Evernote's tech support: https://help.evernote.com/hc/requests/new.