If an Erase & Reset has been finished but there was a drop in the network, or an issue with Apples activation servers. This could cause the unit to start back up with either all or some of the apps missing.
Please first confirm the network connection to the Apple TV, opening one of the default apple apps can confrim this.
Then preform a manual Reset of the unit within the Apple TV Settings app, this will reset and attempt activation again.
Reset your Apple TV 4K or Apple TV HD
- On your Apple TV, go to Settings > System > Reset.
- Keep your Apple TV plugged into its power source until the Reset process has finished.
Reset your Apple TV (3rd generation) or earlier
- On your Apple TV, go to Settings > General > Reset.
- Reset All Settings
- Keep your Apple TV plugged into its power source until the Reset process has finished