Hello
I have some issues with 2 external users where when they attempt to access a canvas app which has been shared with them via an AAD group and that same AAD group is added to SP they get the following error:
We weren't able to add this connection:

Got them to delete cookies and then they get this:

Both users have accepted the B2B invitation
I have checked both the users are in the correct AAD group (same AAD group used for both Power Apps and SP)
I can see both accounts in AAD (possibly nothing, but the )
I have checked in SP that they are appearing as having the correct access to the associated SP list.
Got them to delete cookies and restarting browser
Checked they are not in the User Info List in SP
It appears to me to be a local issue, but out of ideas of what to try next?