cable modem signal / loss of connection

This may or may not be the root cause of the problem (YMMV) but it should be addressed regardless.

The downstream power is on the high side. It may be overdriving the front-end receiver circuit of the modem. And the upstream power is a bit low. That can cause random disconnects, spontaneous rebooting of the modem, speed, packet loss, latency problems, and the unbonding of channels.

Is there a drop amplifier on the coax cable line leading to the modem ? If so, try removing / bypassing it and see. If not, you can try installing a -6 dB attenuator pad such as this one on the coax port on the rear of the modem to knock that power level down and see;

https://www.amazon.com/6db-Attenuator-Pad-1-each/dp/B0013L48XA 

I'll repeat this again for posterity's sake. This may or may not be the root cause of the problem (YMMV). Try it and see. Or book a tech visit and have one installed by them. Good luck !