Xfinity 1GB service. My upload speeds suck

Recently got Xfinity 1gbs service. I'm using Xfinity modern/router, XB8

First few days I was getting 44mbps upload. Now it's been between 0.1 and 4.5mb upload... When it's at 0.1 or so, the Xfinity app will show there is an outage in the area. Once I get notification that the outage is over, the speed goes back up to 3.5 to 4.5 . Really high ping too.

This has made online online gaming jittery / laggy, nearly unusable.

I called Xfinity, and the person I talked to had no idea that 0.1 upload speed is bad. He pointed out I'm getting over 1000mbps download. 🙄

After wasting 40 mins of my time with modem restarts and other things on his end, he proceeded to give me the contact info for the Modem manufacturer...I kid you not.

That's when I said enough is enough and I insisted for the 10th time I speak to a supervisor.

The supervisor acknowledged that everything looks good in their end, but if I am truly getting as low as .1 upload speed, something must be wrong. We scheduled a technician to come, and I agreed to a $100 service fee, but she swore up and down I won't be charged that.

I'm really considering canceling the appointment with the technician, taking the loss to the $150 installation fee Xfinity charged me for the new service. And switching back to Astound. With Astound I had a consistent upload speed of 50-70mbps. Same building cables...(I was using my own router and model)

Any advice?