Internet is not stable

Hello I have been having issues ever since I moved to this new house. Cox had been working great with no issues whatsoever in the previous home. Unfortunately now we cant have a solid connection for more than 1 hour. It's a shame because we pay good money for wifi and use it for work. I have tried everything in my power to try and fix the issue having only a few devices connected at a time, moving the router closer to the middle of the house, checking all the wires. nothing seems to work, we also had multiple techs come in!!!. If I were to guess the issue is coming from the outdoor box but when you mention to them that your wifi is not working and want to sent a tech and the issue is not cox related they want to charge you! I mean my issue should've been fix the day I moved to the new place.  When it does work less than 15 minutes they speed is amazing really fast