Show guest users in Teams Rooms search

Hey folks,

I have a question regarding Microsoft Teams Rooms devices in with guest users in my tenant:

I have invited users from another M365 tenant into my AzureAD.

When I start a session on my rooms device and want to add one of the external guest users, my device could not find them if I search them by name.

It works, when I enter the whole SIP address, so I just want them to be searchable just with the display name without entering the whole address.

Any ideas if there is a solution for this?

Thanks in advance,

Sebastian