@Florian Obradovic I acually have the same when I checked in my client. I guess that is something temporary. I can't see any difference on the contacts and it happens to all users in our directory. I also checked a customer tenant and from the Teams web client and it is the same there.
Wait and see if it is fixed, not a big problem I would say. You can select any of the contacts in the result and come to the same place (chat window).