I'm not the sharpest burrito in the shed, so I seem to always make some kind of technical mistake when I stream. I suppose it's to be expected. I'm old and stupid, and my streams sometimes require attention to detail. I'm not too big on that.
I still haven't figured out why my elgato PS4 streams make my voice a different pitch.
But if you have similar issues, these are some things to check.
Sound. Do you have it?
You have to make sure you have sound coming through to both you and the stream. Game sound, and your own witty commentary.
With the elgato and a PS4, there are some very particular hurdles you have to jump through, both on the console side and the software side (I use Streamlabs OBS).
But let's look at the "easier" setup of just Streamlabs OBS and a PC. You need to make sure you have an sound input for the game that works and for your mic. Sometimes this is easier said than done. My biggest issue currently is avoiding echo and duplication issues. I want sound from my game, but just a single mic line. I sometimes get mic through my game and through my mic, or nothing through both. Or the game gets accidentally muted.
It drives me nuts. I don't know what it is. I swear I'm not changing anything, but one stream will work fine, and the next I sound like I'm in an echo chamber.