Can't embed keypair in MongoDBCompass as a domain user but it works for the admin

Dear MongoDB-Community,

I hope you can help me. I set up a Replica-Set for my work and everything works fine, but unfortunately a normal domain user can’t connect to the database because he is not able to embed the required keypair. As a admin-account it is possible and he can connect to it. Is there a workaround ?

Thanks for your help,