Same issue here. Everything worked fine until yesterday 2/9/25. Today when I opened New Outlook there were no new emails. Tried sending myself an email twice to see if that would work and got nothing. Meanwhile I've gotten at least 25 new emails on my phone's app (not a Microsoft account), but the two I sent myself haven't arrived so it's definitely an Outlook issue. Seems to be completely dead. What a mess.
PS- I'm also on Spectrum but since I'm getting the emails on my phone it doesn't appear to be a Spectrum (or any provider) issue.