Cm500 rythmic blinking of Ethernet light

Hello,

Thanks for reading.

So my ISP had an outage 2 days ago. After when it came back my Ethernet light started a rythmic blinking (not random blinking showing traffic). Also no internet to router. (All other lights solid, ISP confirms internet to the modem)

Plugged into router no internet
Plugged directly into roku or Xbox no internet
Plugged into computer no internet but if cpu is rebooted then internet.

I did the usual power cycle and hard resets. Any help would be greatly appreciated.