Not definite imo to be some sort of cron job. More likely there is some sort of electromagnetic interference happening at that time (a classic one used to be cheap Christmas decoration lights which would be on a timer and cause chaos).

This person needs to get the actual DOCSIS diagnostic logs from the modem to figure out what's going on with the physical line, not just ping tests or speed tests.

Also, why wouldn't starlink be an alternative?

I doubt it's RF interference from something like christmas lights at those specific intervals for 17 months. Also, the author did provide DOCSIS diagnostic logs.

Even if it is RF interference, the problem is at the node level (because his neighbor has the same issues at the same times). So it's not his responsibility to figure out the problem for Xfinity.

Starlink is not an equivalent solution. It's much slower than his requirements, for one.

The author explains in the article they’re looking for gigabit service and Comcast is the only player in the area.