What you have described is an issue with the signal levels. That can be caused by a bad cable wire, a loose connections, or a bad splitter. If you have splitters you can access, replace them, as well as any cable wires you can, from the cable boxes to the wall, modems, etc etc. If that's doesn't help, a trouble call is in order, you will need to contact cax, (call), and request a trouble call. If it's an issue outside the home, delivery of service to the home, there is no charge. If it's an issue at the audit box to the inside of the home, unless you have Cox Complete Care, (I think it's 10$ a month, it could be more now), then to repair indoor wiring, is a 75$ trouble call charge.