I’m afraid that this is an issue that is beyond the scope of what the forum can help with. In this case, you should contact Choice of Games directly by sending an email to support@choiceofgames.com.
In your email, if you include as many details as you can about the Steam deck and game(s) that you have attempted to open, the better.
My guess would be that support most likely will need to work with Valve, in order to to solve this.
Either way, once support receives your email, I am sure someone from CoG will be in contact with you and work with you to get this issue or issues resolved.