ASUS 4G-AC68U - Cellular 4G keep dropping consistently

Hello All,

I'm only using my router as a 4G router and have serious issue as it keeps dropping my 4G connection so often that it's really annoying.

In my settings, the cellular network is set as primary and the dual WAN mode is turned OFF.

Adding my logs HERE

Firmware: 3.0.0.4.384-45149
Modem software version: WWHC050_EU.D61.04.A04

Thanks for the help