Ok, I found the following fix on REDDIT which resolves this problem... many thanks to Boot_Strap_88 for posting
Boot_Strap_88
MacOS - Safari Plug-in Empty Vault - SOLVED
Just wanted a place to publish this since it took some time to work through the issue. After upgrading LastPass my Safari Plug-in stopped working. With 4-5 support calls, I finally got it resolved.
- TURN OFF iCloud Relay - Settings/iCloud/Private Relay - OFF (Do not set it off for a day, must be completely off)
- REBOOT
- Under the plug-in - [Account] - [Fix the problem yourself] - Select [Clear Local Data]
- Under the Plug-in [Account] - [Fix the problem yourself] - [Log out of LastPass Everywhere]
This process was the only thing that fixed it without the issue re-occuring.