Please check speed cap for account.

For a good while I have been getting close to my 300MB cap.  I do speed checks quite often and I do these checks from a machine that is connected directly with the modem and not over wifi.  Some time between my 5/14/20 speed check and a 6/10/20 speed check the speed seems to have dropped from the 290s to a  steady 240MB.  Did my cap get lowered from what it should be for the plan I am paying for?  I will try and paste a graph of the speed drop below.  You can see it is a pretty steady speed and appears to be a cap rather than a various high bandwidth spped drop.