i found a similar case and you could refer to its solution to see if it works:
The solution he recommended was:
- Log in as Admin, open the MS store app and run all of the updates for all apps.
- Elevate the Skype user to the Administrator group
- Log in as Skype
- The skype-mrx error will occur. Press CTRL ALT DEL and open Task Manager (you can since Skype is now Admin). You NEED to wait for the Teams Room autorun thing to "timeout" give it a few minutes. When the screen goes black you will see the task manager.
- Run a new task - shell:AppsFolder
- Run the Teams Room app.
- It appears to set itself as default for skype-mrx. Reboot and test.
- Remove Skype from the Administrators group.