Internet consistently dropping out
I am hoping someone can help me. I have a Cisco DPC3941T gateway. I have the 600 Mbps level of service. Full disclosure, I also have a Synology router.
I am remote working, and I have two who are remote schooling here. Due to the nature of work I do, I am using a desktop connected via an ethernet cable to the Cisco gateway for my video meetings. (Again, more full disclosure - one student connected to Synology route via ethernet, one student connecting via wifi.) I am also using a laptop connected to wifi (although what I am doing on laptop does not require internet connection.)
We are consistently losing the internet. in the course of my four-hour meeting yesterday, I lost it at least six times, which requires me to log all the way back into the meeting and disrupt everything. Of course, the top-level boss was running this meeting.
We also consistently lose internet during the course of the day -- using an Alexa, we'll be listening to the radio (when no one is online yet), the station will drop, and we get a "I'm having trouble understanding now. Try again later."
We can rule out the Synology router as the issue as I am connected directly to the gateway.
When this happens and I look at the gateway, all of the lights on the front remain lit.
I have power cycled the gateway (multiple times yesterday), checked to make sure all the connections were tight and that there were no visual problems with the ethernet cables.
I tried chatting and finally received a call from an agent yesterday who told me that they would send a refresh signal to my modem, and over my objections, told me that since I had internet, I had no problems and terminated the call.
The continuously dropping internet is an enormous problem -- one that is now affecting my job -- and I am posting in the hopes someone give me ideas on how to narrow my problem and have proof so I can get someone at Comcast to actually listen to me and help me fix this. (Frankly, I really believe it's an issue with the cable that comes into the house but I don't know how to prove that.) I'm relatively tech savvy, but I've hit a wall and need and would appreciate any help.
ETA: And of course can't get thru chat or call back to actually speak to someone for assistance.