Inexistent Upload Speeds

I've been living in my new home for almost three months now. When I moved in, the houses were all wired for Cox internet. I went with the gigablast plan, as I need good internet to do what I do (streaming). At the beginning, the internet was great. After a week or so, I would have issues with the internet dropping upload speed for about an hour at a time. When I say they would drop, I mean they would basically be inexistent (dropping below 1mbps upload). Download speeds were always workable. Although,  they are not the speeds I pay for, I can still live with it (usually around 400mbps). Anyway, one day it went out for three hours, so I decided to call a tech out. Upon arrival he stated that there was nothing he could do because he couldn't come inside my home due to COVID-19, understandable. There was then a long period of time where I had relatively no issues. Consistent 35 mbps upload. This past two weeks, the issue has resurfaced and not left. I was streaming one night and dropping over 75% of rendered frames due to network lag. I tested my speeds and got 0.2 mbps upload speed. I told myself, "Okay well it will fix itself in an hour or so, shouldn't be a big deal." An hour passed and it was still bad. I continued to test it every hour for 8 hours and it never stabilized. I called another tech out. They changed out some fittings and connections on the wires and said it was all good. I tested it while they were there and got 25 mbps upload, which is workable. Before they left, they told me that if the issue persists there's only two other things that could be causing the issue: The modem, or the main line (the one that runs to the telephone pole). Later that evening, I checked the speeds again and received 7 mbps upload speed. As a streamer, this concerned me because that is barely enough to stream on. I didn't want to take the risk because I would be dropping frames. This morning I tested it again and got 1 mbps upload, so I went to the Cox store and swapped modems. Came home, hooked up the modem, and got 0.4 mbps upload. I called out another tech to come out tomorrow morning, but it seems the issue is within the main line. I will update this post as I get more answers. Hopefully this issue is resolved in the near future.