hi @JoeDeG and others,
one should consider the spectrum, charter and any other imap/smtp based mail service connectivity issue to be unrelated to the mail service provider settings that have not changed.
also unrelated to iOS [ / iPhone ], iPadOS [ / iPad ] apple mail app or apple app store provided outlook mail app usage. likewise for android and macOS device usage of their respectivee app store outlook app offerings. anyone having issues scenarios is highly likely to just be coincidental and related to some other issue.
also unrelated to apple app store onedrive app usage. if you having issues with that application it is highly likely to just be coincidental.
so far the issue is confined to the windows store app provided outlook (new) app which is why the easiest work around has been to just use outlook (new) > help > go to outlook (classic) menu option to use that alternative windows outlook mail application. that one has demonstrated not having the current imap/smtp mail service connectivity issue outlook (new) store maintained version has been experiencing.