Shared Mailboxes or Calendars not updating since mid Jan 2022 unless disable Shared Mailbox Caching

Jurgen Van Duvel When we tried to fix this using SARA, it created a new profile. This did not rectify the problem. I actually did report the problem on February 8th in our O365 admin portal, but the status was changed to "No issue found".

We enable "shared mailbox" functionality via mailbox delegation permissions ("Read and manage", "Send as", "Send on behalf of"). I do not know if this is technically the same exact thing as the shared mailbox discussion here, but we are seeing the same exact problem everyone here is describing and creating a new profile, disabling/reenabling cached mode, and removing/readding the mailbox delegation permissions has not resolved the problem thus far. Only keeping cached mode disabled works.