We've had an intermittent issue for the past ~8months with our internet failing. Our provider came out a couple of times but didn't find an issue. We just had a guy out again when connectivity was down for two days. He looked up and said, "That doesn't look right!"

The plastic on the coax connector was melted! (The orange coax is their cable entering our house.) We had the power company out the next day. Turns out we had a loose neutral in the meter can. When it would heat up it would cause a high impedance situation and the returning AC would look for other paths to go back. One of those paths was the Coax from our internet provider!

I saw as much as 15 amps on the coax with a load in the house.

Seems the cable modem would shut off send/receive when the issue occurred. Probably protecting itself. Simply tightening the nut holding the neutral lug fixed everything.

Those crazy alternating currents!