Gigablast Slow Speed

Hello,

I recently upgraded my internet to Cox Gigablast but I am not getting the speed that is advertised. 

• Modem - Netgear CM1000 Docsis 3.1 (Swapped twice because the tech advised that the previous modems were defecive)
• Router - Netgear AX8

I have been having this issue since I upgraded and I tried using different computer and I know for sure that the Ethernet port supports gigabit connection. All of my connection tests are hardwired directly to the modem and I am only getting an average speed of 200-350Mbps.

I had 2 technician visit already and they could not figure why am I not getting speed they checked my line and it's showing good signal. I have been reading the forum and it seems that a lot of Gigablast customers are having the same issue, can someone point me in the right direction who to contact or maybe give me a solution to this problem if you have one.

Thank you.