Upload speed issue

With the plan I have, I should be getting 10Mbps upload. For the past month, I have been checking daily and I get anywhere from .6 to 1.5 Mbps. What can I do to get this upload speed more consistent with the plan I have purchased?

I have tried a few guides on network config settings.

The PC I test from is cat 8 wired directly to the COX supplied modem/router.

I test from many different sites including the COX speed test site.

I have tested from several different devices on my network and they are all reporting the same range.

I have swapped out network cables as a “just in case” measure.

At this point, I am out of ideas. Does anyone have any other thoughts?