We have a "Corporate Calendar" group setup for people to add events that impact everyone in the office. It was setup in July 2020 and has worked perfectly until last week. On 4/7/2023 multiple users had this group calendar stop working in the Outlook app. After a reboot it started working again. Then today it stopped again for a few people (not everyone). It does show correctly on the Outlook web page (https://outlook.office.com/calendar/view/week).
I've checked the following via PowerShell and all groups show False which should be correct:
If I try adding this group calendar to "My Calendars" or "Other Calendars" I get the error "To add a group calendar, join the group and the calendar will be listed under All Group Calendars."
I've also tried to restart Outlook numerous times.
I am an owner and a member of this group.
Group calendar setup:
O365 info:
We have a Microsoft 365 Apps for Business subscription (not Premium).
Outlook app info:
Microsoft® Outlook® for Microsoft 365 MSO (Version 2303 Build 16.0.16227.20202) 64-bit
Has anybody else run into this issue and if so, how did you resolve it?