See what is the right settings for outlook for spectrum email - Microsoft Community where the interim work arounds, until outlook (new) store app gets an updated pushed that fixes this, are . . .
a) if you can revert store app install from outlook (new) to outlook (classic) using the help menu > go to outlook (classic) button option
b) configure outlook (new) store app using pop3 tls/995 instead of imap tls/993 same incoming mail server
c) use spectrum web app mail solution https://mail3.spectrum.net/ or alternative mail app in store supporting imap/smtp connections