1 Gigabyte Service plan barely 250mbps

As stated in the title, I have the 1gbps service plan, and right now I am barely getting 250mbps. I scoured the internet to see if Xfinity was throttling connections but was unable to confirm. I did plug my modem directly into my pc and received the same results as when I was plugged into the router. The modem, Netgear CM1200, is on the approved list and used to get around 950mbps. The router, which was a Netgear AC3200, is now an Asus AC3100 I have rebooted, unplugged modem and router numerous times. I even bought a new router and the 250mbps problem still persists. If Xfinity is slowing my connection due to the pandemic, I would understand if something was mentioned or e-mailed. Instead, I got a bill for the full 1gbps plan. I am hoping that next month's bill will reflect the time that my connection was disbanded. Please help fix this issue or put info into my hands on what the issue could be. 

Thanks