TP-Link Archer C7 v4 WAN port randomly loses connection

running 18.06 on it and it has no issues for 72 days(uptime) then suddenly it failed to reach internet. Local wireless and LAN are still functioning as expected.

Rebooted the router and cable-modem fixed it sometimes but not always, check cable-modem status it did not show any issues, it looks like the WAN port on Archer C7 v4 has issues unrelated to software all of a sudden.

Tried newest 18.06 these two days, same issues, the C7/v4 now becomes so unreliable that it is useless.

Where can I find an "industrial class" router for home usage? Tired of failing "cheap" routers these days.

Meraki and Ubiquiti devices are definitely above consumer grade. I'm sure there are other brands available, as well.