It's possible:
* He is a relatively new or less prominent figure in the industry. It's possible he has done some smaller projects that haven't gained wide recognition.
* He uses a different name professionally. You might be thinking of an actor with a different name.
* You might be mistaken. Double-check the spelling of his name and any other details you might have.
To get more information, you could:
* Check online databases: Search for his name on IMDb, The Movie Database, or other movie/TV databases.
* Use social media: Search for him on platforms like Facebook, Twitter, or Instagram.
* Look for local theatre productions: If he is an actor, he might have been involved in local theatre productions.
Let me know if you have any other information about Mathias Eysen that might help me find more details about him.