Presence in Microsoft Teams can't be viewed or updated

5/5/20, 4:40 PM: This issue appears to be resolved, but Microsoft is still working on the root cause. 

*****Original Message Follows*****
5/5/20, 3:00 PM: Many users are not able to view the presence of others in Microsoft Teams, or update their own presence (e.g., available, away, busy). This is a problem affecting all Microsoft customers, and they are working on a resolution.