NW FL by chance? don't have to answer if asking too much. It's not Twitch, or OBS. Twitch Studio and YouTube have the same results. Either I get above advertised speeds, or speeds below what my Verizon iPhone is capable of.
In my case it was something wrong with the tap on pole, and now they think its noise, which it very well may be.
Email Cox.help@cox.com you name, address, and a link to you post. They can get you a tech out. when the tech comes make sure they test your speeds on their handheld, directly from the coax, until this is done no progress will be made. I don’t know what service level you have, but you should see speeds that are at or very close to what’s advertised, ie I’ve had slightly above the advertised gigablast speeds for years.