"Quality of Service (QoS) is used to set up priority to specific devices, services or applications within the network through the router, so that the maximum amount of available throughput and speed can be used."
https://www.linksys.com/support-article?articleNum=137079
QoS allows you to prioritize bandwidth for specific clients, services or programs.
Basically it takes your connection and allocates bandwidth to your target machine before the rest of the network.
For example, you might want to prioritize your hardwired PC, you say that's most important. But others may want their VoIP or xbox to take priority.
I played with QoS in the early days but I've never had a real need for it. My connections are usually top tier.
If your connection is under 50 Mbps (obviously yours is) then QoS might not just help... it might be necessary.
Here's a good guide on the subject >> https://www.howtogeek.com/75660/the-beginners-guide-to-qos-on-your-router/ (the ads are extremely painful and they link to the wrong test but good information on QoS options and features)
If your router doesn't support QoS I'd recommend the Netgear Nighthawk AC1750. You can get them as cheap as $35 used. Search the Nighthawk AC1750 manual for QoS (page 49)
Having explained that. It looks like you've had a little improvement. But it's still spotty.
91Wagovanman's Speed Test Results
Maybe weather or dish placement are be to blame. What does HughesNet have to say?
You should run an automatic speed test. Here's some settings I might try for your connection. (Considering the bandwidth limitations and data cap.)
A longer test will give us more information.