microsoft oauth service - username missing

[vancouverdeveloper]

We were able to connect to our onedrive but cannot see any content.

then I notice that our oauth azure ms system account is not connected.

so I tried connecting and got this error

Error: Required field

More information about this error

Debug info: username: Required field
Error code: invalidpersistenterror×Dismiss this notification
Stack trace:
line 497 of /lib/classes/persistent.php: core\invalid_persistent_exception thrown
line 645 of /lib/classes/oauth2/api.php: call to core\persistent->create()
line 163 of /admin/tool/oauth2/issuers.php: call to core\oauth2\api::connect_system_account()
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Output buffer:
Notice: Trying to access array offset on value of type bool in /ourfolder/moodle-4.1.7/lib/classes/oauth2/api.php on line 641

any ideas why?