Intermittent Dropped Connection - Comcast not helping

Hi. I've seen numerous posts and solutions on this. I believe it's the upstream power level on my modem. Only problem is Comcast REFUSES to even look into it. After several weeks I'm still being given basic solutions that are not working. I've reported Comcast to the BBB over them not taking this seriously. We work out of the house now and lose time at work due to outages that cannot be recovered. Comcast or satellite is our only choice in the neighnorhood. We had RCN at my previous address and it ran flawlessly (except when Comcast came to my neighbors and disconnected our RCN and hooked their service up. The refused to fix that at first although they tried to convince me to switch since it was already hooked up).

About 3 weeks ago our connection started dropping intermittently. Anywhere from a few minutes to a couple hours. I tried all the suggestions from support. Sometimes they worked although the service would cut out again. Many times it did not work. I looked at the Modem setup (Arris SB6190). All my equipment is two years old and well within spec. I know the issue is not with wifi as the modem lights blink as they would when service is interuppted. I proceeded to call Comcast for help.

The reps are nice. They went through all the basic thinigs I tried. Restarting and resetting the modem. Same result. Sometimes it worked but would usually go out again within the next hour. One tech said there was a problem with the line outside the house. Great I thought. They sent a tech, who was nice, but he didn't even have these notes. When I mentioned that he just shrugged. He wasn't going up any pole I guess. He checked the connections at the house, which he said were older but looked okay. He replaced them anyway and left. Service went out 30 minutes later. Talking to techs now they say there is no record of any issues woth the line. So now they ignore that as a possible problem.

I called another time and they said this was due to work in the area and would be reslved that day. Great I thought. The dropped connections didn't stop happening. 

I called again and this time they said that maybe it was the modem. I doubt this, but we should try everything. So, they're sending me a new modem. I'll try it but I have no intention of being ripped off with any equipment rentals. My modem and router are both approved by comcast and well within spec. I'm trying the modem and sending it back asap so I'm not charged. Because Comcast will make you do this, but not for free. 

The modem arrives next week. They told me to go INTO a store to get it sooner, but I refused becasue of the Covid. That's on me. In the meantime the connection still drops. I called Comcast again to explore other options. The issue with the line outside never went anywhere. I started going into the modem setup to look at logs and everything else. It appears the downstream channels are within their recommended range (Avg -2.00dBmV Bonded). The upstream channels seem too high (55.00 dBmV Usually unbonded). I asked about this too and they didn't know what I was talking about. The tech did know know what these setting were nor did they know what bonded and unboded channels were. Unbelieveable. 

Once they saw that I had a modem coming they started to make excuses as to why they could not pursue this further.  I was being transferred to Level 2 support finally and the tech stopped it. They said I needed to wait for the modem. I pushed back. They said they could not  connect me to level 2 support becasue there was no support ticket for this. What!?! Create one I said. They said they had done everything they possibly could and I had to wait. That's when I started losing my patience. I asked about the channel levels. They told me they didn't know what that was so I explained. They told me I had a great conenction, refferring to my download speed. I replied that download speed is not a measure of the quality of the connection. They said they would loon into this and get back to me. They never did which was what I expected. 

Comcast has been a failure on this. Also, there seems to be zero communication between reps and their notes they should be taking. I have to explain from scratch every tome. These alleged notes never seme to make it to techs in the field. I'm explaining thing to them from scratch as well. It's the height of unproductivity. We're still trying to work with the connection cutting out. I download and transfer large files. They get interuppted often.

To summarize. Our equipment is:

Modem: Arris SB6190

Router: Netgear Nighthawk AC1900

House was recently renovated and new cable line run from basement to IT closet  on second floor about 30 feet away. No splits. Line comes from outside into a 3 way and cable out from that upstairs. Service worked fine for almost 10 months before these issues. Upstream was never bonded (was with RCN). I figured out now that I can disconnect the cable, wait for the modem signal to stop blinking, power the modem off, reconnect cable and power on. It usually conects. Comcast techs ignored this too.

 Not seeing where I can attach images. I have screenshots and the log. I'm hoping this helps to get this escalated. Comcast has refused to look into this beyond the most basic fixes. I have been peristent and yesterday was the last straw. If I had another cable internet option I would cancel Comcast immediately.  I already filed a compaint to the BBB. Thank you.