On July 6 I installed the updates v16.63 (2207500) and in New Outlook the signatures from all four of the email accounts I have, have all disappeared. They are not visible in SIgnatures, and the '+' button in Edit Signatures does nothing – I can't recreate the signatures. I've upgraded to v16.63 (22070801) but no change.
I switched back to Legacy Outlook nd the signatures were all there, and I could edit and add signatures. Switching back to New Outlook, my signatures had reappeared, but once I restarted my MacBook, in New Outlook the signatures are not present and I cannot add any.
MacBook Pro (2012)
Mac OS Catalina Version 10.15.7
Microsoft 365 Business Standard
Any help gracefully received. I've tried the customer Customer Support button but the chat responses are painfully slow - conversation has been going on since July 7th with diagnostic questions taking 18-48 hours to appear.