@bongov 

If you know the range that the ONT (fibre connector) is giving you then setting a static address might be a good choice, that way its not going to lose DHCP. 

However if its dropping a DHCP address, then likely this is the ONT and not the router, its the ONT after all that hands out the DHCP to the router WAN port.   I would try static first, if that doesnt help or work then try accessing the ONT (if possible) and extend the lease to 8 days or something like that..

  @Philbert I tried setting a static IP, but it doesn't work since the ISP enforces DHCP. 

I tried connecting directly to the ONT, and had no issues with dhcp drops. 

I ran a ping plotter as well on the direct connection, no issues. 

It's isolated to the AX55. The ISP says that TP-link has an agressive DHCP setting compared to other manufacturers. 

Unfortunately the "Advanced" settings in the AX55 is on such a low level that you can't really do anything about the WAN DHCP settings.

  @bongov 

Sounds like you have covered all the things I had in mind...  :)

  @Philbert

Now it's popping out entirely different logs: 
 

2023-06-13 10:50:28 Led Controller INFO [1167] Start to run WAN1_OFF

2023-06-13 10:50:28 Led Controller INFO [1167] Start to run WAN0_ON

2023-06-13 10:50:28 Led Controller INFO [1167] Start to run LAN_ON

This keeps happening. Might replace the router entirely for one with more advanced settings. 

Too bad TP-link dumbs down their products.

  @bongov 

Will you lose internet access when those logs pop out? Or internet is actually working fine?