We826-t2 4g connection down!

Hi, I configurated my WE826-t2 with 4g connection. It works but I have a problem. After a few hours of using it, the 4g connection gets down. Then it gets up, for a few minutes and down again. I m using the openwrt-we826-GO2020-03-01-upgrade.bin, I don't know where to find a log, to understand what is happening with the 4g connection after a few hourst that it starts to flap.
Can you help me?

On the command line: logread

On the web GUI:

  • Status > System Log
  • Status > Kernel Log

Also, this thread implies it may have been a power issue. Are the two threads related?