Streaming to twitch

Hello,

I am having a ton of issues after switching to Xfinity and now attempting to stream. Time after time I have called and have been told my issue is fixexd. I don't know what else to do at this point so I am posting here. I pay for the Gig internet to specifically for the upload speed. I constantly have 30-40 upload speed but still cannot stream to twitch. I am trying to do 720P at 48 frames with a 4k bitrate and still cant do it. I dont understand what the issue is but apparently I am not really getting the upload speed I am being told I am or I am being throttled into my stream which seems to be realistic. I am not sure what to do at this point and was hoping for some advice. I am at the point where I would leave Xfinity and go back to verizon if I could but verizon is not offered in my apartment complex