field176 wrote:
The tab key on my new 2020 MacBook Pro 13" has suddenly gone funky. When in an application (EXCEL, Quickbooks, etc) when I tab to the next field, the cursor doesn't move, but in the application there appears a blue outline on the app executable tabs (little page size dots , etc) but no tabbing in file.
Are you saying this is within the application(s) your EXCEL, Quickbooks, etc.
Try a SafeBoot How to use safe mode on your Mac - Apple Support login and test, reboot as normal and test.
or
you are referring to the HUD (Heads Up Display) Command Tab ?

I have noticed some bugs introduced with the HUD in Monterey which seemed better with the point updates.
The current stable released of Monterey macOS 12.3.1
Keep your Mac up to date - Apple Support
Keep your Mac up to date - Apple Support
if no insight or resolve you can file a bug report, same link as here:
you can submit your Apple Feedback Feedback - macOS - Apple