Slow speeds through powerline boxes after internet upgrade

I have been running a set of Netgear PL1200 boxes within my home for the past 3 years. Last week we upgraded from 25 MPS to 50 MPS Internet. A technician came and replaced the router that also control U-verse. 

I am achieving 40-50MPS on a direct line from the router and about 35MPS on wireless near the unit. The power lines running to the upstairs of the house are getting 3-6MPS. With the previous box and service at 25MPS I was getting 20MPS from the powerline box. 

Has anyone else experienced this? The PL boxes have worked great, I doubt they failed at the same time of the upgrade. I’ve reset them along with the router and have had no luck. When I test the internet speed from the boxes, it shuts downs the u-verse network TV and all. I’m guessing this new AT&T box isn’t liking the powerline boxes or making it think the internet isn’t secure.

The boxes run to a bonus room where the WiFi is at about 7-10MPS, so the boxes are much appreciated especially for my PS4. Running a direct line would be best, but I really don’t want to go through an unfinished attic full of insulation to set it up if I don’t have to.

Thanks I’m advance.