The frequent buffering is due to a combination of congestion, latency, and network management strategies due to the pandemic. Sunday night would be a time when a lot of people are trying to do the same thing you were trying to do, stream. This puts a huge strain on the system, and slows everyone down. Since satellite internet is a limited capacity system, this is a normal ocurrence during prime time. With the pandemic, this is worse, and it may not improve any time soon.
Satellite internet also has high latency, which if congestion is low is normally not a problem, but if you add congestion to it, it can make streaming difficult or impossible.
Finally, during the pandemic, HughesNet has deployed network management strategies that deprioritize streaming, so it's harder to stream than it was before (but not impossible).
In short, many issues are affecting your ability to stream, and while it's possible to stream on satellite, you may not be able to stream on demand at all times. (It will also eat up your data very fast...just FYI).
We just installed internet and then installed Youtubetv to manage our tv choices on a Smart tv (Roku). We were watching a movie on a local station Sunday night and had frequent buffering. Would the purchase of a WiFi booster be of help?