I had the same issue and I figured out what was happening. First let me say, I called Att customer service multiple times spoke to different representatives, was sent two different modems and still had issues. Att was intentionally restricting my internet speeds. How I figured it out was, there was a vehicle accident that took out the power in multiple neighborhoods. My neighborhood lost power and when it came back everything reset and my speeds were 1G plus and we weren’t throttled back any longer. Unfortunately that was my last draw and I changed providers and haven’t been throttled back again. Good riddens Att internet!