"How can it just fix itself?"
The cause of the error may be intermittent. When the cause stops, so does the issue. The next step is to figure out what's causing the interruptions. Is it weather? (many things such as high winds, thick clouds, and others can interrupt the signal; wind can cause the satellite dish to move a bit; trees can also interrupt the signal if they're waving in the wind, etc.), is it technical? It may take a while to figure out, depending on what it is.
When you experience the issue, what is the state code? You can find the state code by opening a browser and going to the modem's page. The code will have 3 numbers: 0.0.0 means everything is fine. If the numbers are different, they indicate a specific issue. You do not need to be connected to the internet for this, but because the wifi appears to be a little wonky, you may want to connect your device directly to the modem to be able to see the modem page.
Post the code here, because when you're not seeing an error, the Hughesnet reps from CS or on this site may not see it either, because there isn't one to see, so they might need to know what the code says. They can dig into your system a little more to find out what may be happening, but the code is typically the first step.
The reps here are no on 24/7; they usually work business hours, with one or two of them sometimes working later than that. They will respond to you here and may ask you to send them a private message (they will provide a link for you to do so). You will recognise the official reps here because they have the label MOD next to their handles. The rest of us are fellow subscribers.
What device(s) do you use? Phone, desktop, laptop, tablet...?