AT&T Fiber connection slower than usual

I just noticed in the past few days that my fiber connection has slowed to about half what I typically would get.  Before with a speed test I would get about a 1ms ping latency and would get between 900-950mbps download and upload speeds on my hard wired PC.  Doing a speed test now on the same PC I'm getting 15-20ms pings and only about 400-500mbps speeds.  Nothing has changed with my setup inside the house.