The beachballs and massive typing lags are so bad now I do most of my real-time note-taking in the native Notes app and then later transfer to Evernote when its beachballs aren't as disruptive. Evernote loves beachballs, apparently. Pro user since 2012 with only 116 notes (though some are biggish running threads). Macbook Pro Touchbar 2.9 GHz Intel Core i7 with gobs of free HD space and available ram. Systems and apps all up-to-date.
Encountering the same issue recently. Fwiw, I get the Keychain dialog on every wake-from-sleep... Glad to read that it's being tracked. Any confirmation that a clean install of the MacOS Evernote app resolves the problem?