Internet connection continuously keeps cycling on and off

So my internet has been very finicky the past week after a supposed maintenance to increase speeds in the area but ever since the maintenance my internet would never be solid for a day. At MAX maybe an hour or 2 before the xfi modem would turned from the solid white to a blinking green. I’ve had a tech come by the house already, switched out our modem because we were told to believe that the previous one was overheating but that wasn’t the case as the problem persists. I’ve even gone out of my way to buy a new modem that supports xfinity and that worked for about a couple hours as well but turned out to have the same problem which left me to think it was an issue with the cables then. I went out the next morning to buy a new coaxial that i replaced with the old cable that was there and even that didn’t work with both modems(new modem i bought and xfinity modem) so know i don’t even think it’s an issue with my house but the maintenance that was done around the area. Any help that i can get would be much appreciated, maybe something i overlooked, but i feel like i’ve tried everything and if this tech can’t find the problem, i’m probably gonna switch providers