MOCA Speed Significantly Slower <24 Hours After Installation

I have a 2GB plan with Xfinity. I do not have ethernet ports in my office, and hooked up MOCA yesterday. I am not using the built-in Moca with the XB8, as it was much slower yesterday. All day yesterday my speeds were sitting at around 900 mbps, and that's because I was only using a cat 5e ethernet cable and not a cat 6. Today, I get on and my speeds will not go above 150 mbps. I did not touch anything on my moca adapters, on my Xfinity router, or anything that would've caused a difference in network. I am using the two "highest" ScreenBeam adapters purchased from Amazon, and have one adapter hooked downstairs to my router and the other coming through the coax port in my office upstairs. Any advice as to why this giant gap in speeds would be happening without anything changing overnight would be greatly appreciated.