Using classic Outlook for Windows in business environments
Same issue for me - stopped working early February for one IMAP account, and now seems to have disabled my other IMAP account. Chatting Spectrum yielded the same response many here received - they suggested I use their webmail only and IMAP is no longer supported. I find that hard to believe, but I'm definitely looking to disassociate my accounts with any ISP email addresses go-forward - should have done it a LONG time ago...
Spectrum's web interface is ungodly slow...basically unusable. Sure hope this gets fixed soon, but if not, I'll be monitoring emails on their web application until I can complete the switchover!