I tried "Press Menu and TV Home" on my remote
The remote seems fine then, but that is not what I wrote. Just a single tap of the Menu button alone should get you out of CRD. Optionally, that might ask for a PIN number, if so configured. (Unless it is even more complicated: ↴ )
If you got the device from some organization that had configured it with a device profile to be used ONLY for CRD, and if they didn’t remove the device profile, then the unit may need to be restored. For the 4K model, that restore is unfortunately not a home user option, and has to be done by an Apple technician, so you will have to bring it in to Apple or an Apple Authorized Service Provider. Restore your Apple TV - Apple Support. You can contact Apple Support for restore options.