Slow Internet on 2Gbps Plan

I’m on the Xfinity 2Gbps plan using anXB10 gateway and a Realtek 2.5GbE Ethernet adapter with the Wi-Fi 7 wireless. My wired speeds should be close to 2000 Mbps, but I’m barely getting 800–1500 Mbps on average. Sometimes it drops even lower.

Here’s what I’ve done so far:

1. Upgraded to aCat6a Ethernet cable

2. Confirmed my PC supports2.5Gbpsand updated all network drivers

3. Restarted and factory reset the XB10 gateway (had a technician even swapping the xb10 for another one - visit cost was $100)

4. Checked aggregated link speed — it shows 2500/2500 Mbps, so the gateway seems fine

5. Verified my plan and data cap through the Xfinity app (even though I purchased 2gig plan it shows 1.2gig the advisor said its an issue on their end, but I'm supposed to have 2gig)

6. Ran multiple speed tests at different times of day, both wired and wireless (the Xfinity speed test doesn't even work and gives me an error message)

7. Ruled out my PC as the issue with hardware/software testing

8. Tried changing adapter settings but went back to default

9. Tested different Ethernet ports on the gateway (ethernet should be fast speed but its not.)

10. Power-cycled everything multiple times

Other details:

• I’m only testing on asingle device, no heavy uploads or downloads running

• This happened before the upgrade to the xb10 and 2gig, customer support said on the phone that xb10 is known to have issues.

• technician confirmed that my area had an issue or error but said "its fixed", still having same problem with speed and dysconnectivity.

At this point, I’m wondering if:

• the xb10 is just junk and I can downgrade to a different one like xb8 while having to 2gigs

• There is for sure multiple issues on Xfinity’s end including the speed they have allocated me 

• Something needs to be configured in my account backend

• Or if there’s any known compatibility issues with 2Gbps plans and my area

I’d appreciate any help, especially from someone who can look deeper into my account or network settings on your end. I’ve spent hours troubleshooting and just need stable speeds that match what I’m paying for.

If I won't be able to get the service I am paying for or a fix in the next 30 days, I will have to either file a FCC complaint and/or file an arbitration with the AAA bureau.  

Including this post are 11 recorded calls and conversation with the technician. 

GIVE US WHAT WE PAY FOR. If you can't deliver that speed, then refund me and give me the right one.

Thanks in advance.