Slow Gen5 download speed

I am with Hughesnet only for about three months --- initially good for the first few days, and then for the past 2.5 months download speeds are very low and volatile. I am using Windows 7 OS with nothing fancy installed; Hughes HT2000W modem. My main use is work related up-/ and down loading of relatively large CAD files, and well as remote CAD work (using OnShape). I have contacted the tech support but to no avail. It appears that the tech support cannot do anything about slow download/upload speeds and high volatility in speeds (see data below). All speed test data is recorded at my Hughesnet account speed test site.  I have not experienced this bad of a service ever before with any other internet service provider. And, the problem is not in my computer or system, as I have tested three different computers, changed configurations, am directly hardwired to the modem, disabled everything I possibly can in order just to focus on the download/upload performance. I am also not streaming anything but use the connection for work and up- /downloading files. With all the arrangements, and all three computers, I am getting about the same results. The problem appears clearly to be at the Hughesnet end. It appears (and this is a hypothesis) that Hughesnet, in order to manage their overall traffic, throttles individual services down regardless of the level of the individual contract (and I have the highest available data contract and commitment). I, honestly, cannot recommend Hughesnet satellite service to anyone. My previous service provider was Comcast and prior to that AT&T. I never had to conduct "speedtests" as the connections were always stable and services predictable, and speed (down/up) variablity (measured as standard deviation) was within (+ -) 5 Mbps.   

Here are some of my latest results from the hughesnet site (in total I have abot three months (from 10/1/2017- to today) of speed data):