In addition to the automatic network search, the LG unit can also select the network manually, and once the network has been selected manually, it will not switch to another network if reception is also lost.

Depending on the environment and model, the network search can take a long time.

Android 9 | LG UX 9.0
Select network manually -  Open the  Settings
Select network manually -  Tap on  Mobile networks
Select network manually -  Tap on  Network operators
Select network manually -  Tap on  Search networks
  1. Open the Settings
  2. Tap on Mobile networks
  3. Tap on Network operators
  4. Tap on Search networks

LG Instructions