Using older versions of Outlook for Mac for personal email and calendar
I have the exact same problem. It started this morning. I am using Microsoft Outlook for Macs Ver: 16.63 (22070801) the license is for Microsoft 365 Subscription. When I revert to the Legacy version of Outlook all of my signatures appear and they are editable. When I switch back to the new Outlook they are gone again.
MacBook Pro (13-inch, M1, 2020)
macOS Monterey v.12.5
Microsoft Outlook for Macs Ver: 16.63 (22070801)
Microsoft 365 Subscription
Chip: Apple M1
Memory: 126GB