HTC U Ultra has a persistent problem that cannot be solved, you can perform a factory reset (also called a hard reset or master reset).
A factory reset reverts the phone back to its initial state—the state before you turned on the phone for the first time.
Important: Factory reset will remove all data on your phone storage, including apps you've downloaded and installed, your accounts, your files, as well as system and app data and settings. Be sure to back up any data and files you want to keep before you do a factory reset.
Home screen, tap
To avoid deleting media and other data from your storage card, make sure you do not select
the Erase SD card option.
- Tap Reset phone.
Note: A factory reset may not permanently erase all data from your phone, including personal information.