I understand you are having problem with an added account that previously synced, but when you click that mailbox in Outlook it stays on a continuous loading spinner and you can’t open Inbox or any folders.
Because this is a custom domain mailbox (@myghm.org), this is most likely a work/school (business) mailbox. Could you please confirm:
- Is the @myghm.org address a work/school mailbox managed by your organization (IT/admin), or is it a personal mailbox you control?
- Can you sign in to that same mailbox in a web browser (Outlook on the web / your organization’s webmail), or does it fail there too?
Look forward to hearing from you. Have a lovely day!