Hi. I've also been having this problem since moving to the EverNote Web V6.18 version. The message appears even after daily re-boots. Using the web version of EverNote on Win8 laptop and Firefox 80.0.1 (64-bit) in private mode.
I'd love to know which browser settings are causing the problem.
The new version of EverNote works using Chrome in incognito mode.
(Could this be a strategy to get people to use Google products?)