If the time or date is set manually once, the automatic time/date can also be activated again afterwards, and the LG smartphone then obtains the data via the mobile phone network.

Android 9 | LG UX 9.0
Step 1:  Open the  Settings
Step 2:  Tap on  General
Step 3:  Tap on  Date & time
Step 4:  Enable  Set automatically
  1. Open the Settings
  2. Tap on General
  3. Tap on Date & time
  4. Enable Set automatically

LG Instructions