A soft reset or restart is the first recommended repair for minor software faults that may have caused your iPhone X to constantly lose the signal. Follow these instructions to restart your iPhone X from the settings menu:

1. To access the Settings app, tap it.
2. Select General.
3. Scroll down to Shut Down and press it. After then, your iPhone will shut off.
4. To turn your iPhone back on, tap the Side/Power button on the right side after 30 seconds.

1. For a few seconds, simultaneously press the Power/Side and either Volume buttons.
2. Swipe right on the slider to switch off your smartphone when the Slide to Power Off option comes on the screen.
3. To turn it back on, hit the Side/Power button again after 30 seconds.
4. A soft reset will not wipe your personal information or other important data from your iPhone X's internal memory, so there's no need to be concerned about data loss.