MicrosoftBig thanks Sohail_Tariq , the clearing the path:
C:\Users\Skype\AppData\Local\Packages\Microsoft.SkypeRoomSystem_8wekyb3d8bbwe\LocalCache\Roaming\Microsoft\Teams
solved the issue that there was old name on the screen.
But what you then wrote:
"We are working on adding clearing cache from TAC capability for IT/ device admins."
I really wish to see a day, when nobody needs to clear the caches on Teams . Teams should be smart enough to understand when its cache is dirty and it should be updated. By adding possibility to clear the cache is in my mind just wiping bad things under the carpet and closing eyes from real facts. It is very hard to believe that there cannot be possibilities to detect when the data in cache is dirty and requires refreshment. But when looking for my feedback, it seems that I'm quite alone with my thoughts 
Fix the cache on Teams, don't ask users to clear the cache.
