Really odd modem problem that happens at a random (but mostly constrained) time of day.
I'm hoping you might be able to help advise me on a puzzling situation with my Technicolor CGM4140COM modem. I've had Xfinity out a number of times to fix but they can't identify the issue without a repro.
Any devices connected to LAN and Wifi will lose network connectivity - as if the modem is suddenly rebooting. It shows no physical signs of rebooting that I can see.
- Both LAN port lights slowly flash at the same time
- XFi app from phone (accessed via cell network) says it can't connect to the modem
- Local network comes back first
- Internet comes back a few minutes later
- Once the connection comes back I'll resume whatever I was doing (eg. streaming video) and often the connection will drop again in the same manner and take a few minutes to come back.
- This happens almost every day but days can go by without it happening.
- This happens mostly between ~10:30am and ~2:00pm. Very rarely earlier or later than that.
- The modem logs don't show any evidence of issues - the uptime/LAN/Wifi uptimes are all as expected (eg. 10 hrs uptime when this problem happened 20 minutes ago).
- This didn't suddenly start happening during covid homeschooling, it's been happening for at least 2 years now.
- I do go over the 1.2Tb cap each month.
- The modem is in a workroom and connected directly to the cable socket.
- The big Xfinity adapter thing with the green light is down by the TV connected to a splitter.
- Up/Down Power and SNR seem to be within tolerances.
Some random events that (by coincidence? happened at the same as the connection dropping:
- Door slamming.
- Doorbell ringing.
- Electric kettle boiling.
- Load aircraft overhead.
Any thoughts really would be greatly appreciated, especially as this is now impacting my kids ability to engage in online classes effectively.