The LG device automatically switches off the WLAN hotspot after 5 minutes when no devices are connected to the LG, this timeout can be adjusted or even switched off completely, so that the WLAN hotspot remains switched on until it is manually deactivated.

Android 9 | LG UX 9.0
Step 1:  Open the  Settings
Step 2:  Tap on  Tethering
Step 3:  Tap on  Wi-Fi hotspot
Step 4:  Tap on  Timeout
Step 5:  Choose desired  Timeout
  1. Open the Settings
  2. Tap on Tethering
  3. Tap on Wi-Fi hotspot
  4. Tap on Timeout
  5. Choose desired Timeout

LG Instructions