@Joseph-TP For three days I have done the following: ONU EPON - switch not configured - AX50 and the problem with the WAN port disappeared! Most likely there is a software problem between the AX50...

@Joseph-TP For me, changing the DNS server does not help, the problem continues. I use an ONU EPON from my provider, I replaced it with a new one, the problem continues. The AX50 router was replaced...

I have a problem with the AX50 router, it disconnects from the internet for about 30 seconds, when this happens in the router logs I see this...