It's not just 365. I'm running Office Home and Business 2019 Retail on two machines and Office Home and Business 2019 installed from my Microsoft Account on a third one. I am only have this problem on one of the Retail installations. The others work fine. I tried the reversion to the previous version which didn't work and I tried the DNS trick which didn't work. I have done Online Repairs and uninstalling and reinstalling Office and even doing a Repair Reinstall of Windows 11 Pro. Nothing seems to solve the problem on the one machine.
I am working with someone on another thread who has given me several suggestions, but the problem persists.
I don't know if it's Microsoft or just my machine, but it appears that this is not an isolated problem.