Upgraded to Gigabit internet with issues

So in late June we upgraded to Gigabit internet and it came with some headaches and left me with a kinda bad solution.

I got the new equipment on a Saturday, hooked it up, went to the backend to turn on bridge mode cause I have my own mesh routers. Everything is working fine, a couple hours later the internet completely drops and I noticed I am no longer getting the speeds on my plan. My speeds now with it working are usually 900-940 down and 40 up but I was getting like 30-50 down and 40 up(upload was always consistant).

So I decide to call in, agent on the phone couldn't help so they schedule a tech to come out. He comes inside, removes a couple of old splitters we had running, cleans up wires, etc. Problem still persists and he claims it must be the line from the pole to the home. So we schedule a line tech to come out, he comes a day or so later and tests the line from the pole to the house, says hes getting over 1gb at the pole and the line at the house(upload also fine). He says it must be inside.

I have another tech come out and we tested everything, we even brough the modem outside and plugged right into the line from the pole, still the same issue. I ended up going through 6 techs; 2 line techs, 4 regular techs. 9 days of internet downtime. I think 4 or 5 modems.

The solution the last tech said after he installed my current modem, don't go to the backend and sign in. I skipped that option and the internet has been working ever since. 

My issue now is that I have these very feature heavy mesh routers and I have to eliminate a lot of those features because I have to leave the routers in access point mode to get around having a double NAT type issue on games and such.

I had been using the routers in access point mode for a bit and I decided to purchase my own modem last week. This modem was one with no routing capabilities and activated it with a tech over the phone, it was working fine, except it crashed on the first day once. I didn't think anything of it until a few days later, it crashed again and I noticed the phone line light never became green. I called tech after the second crash and had them resend signals and the phone line never activated. I was so frustrated from previous issues that I just said forget it and went back to the Xfinity modem with my routers back in access point mode.

My question is, how can I go about enabling bridge mode without going into the 10.0.0.1 area? If I call tech support and have them turn on bridge mode, will they be accessing the same backend therefore causing the same original issue?