RAX120 with iPhone 11 pro wifi 6 client. get half download speed 2-300 Mbps, but upload is 600 Mbps

I've been having issue with netgear model! I've bought the costco model RB840 Orbi. CC told me it's the device issue. So I bought the RAX 120 to see if it resolves my issue, but same issue!

With iPhone 11 pro wifi 6 client, I get half download speed 2-300 Mbps, but upload is 600 Mbps...I've upgraded FIOS gigabit and hardwire is 900+ for both. I've seen on youtube with all wifi 6 clients (iPhone 11 and Samsung S10) that you can get 6-700 Mbps over AX wifi 6...

Whenever I use Frontier server speedtest, I've gottan this speed. However, when i go to odd named once, Gemnet? it could go to 6-700 Mbps downloadd. I figured the provider speed test is more accurate tho.

Also, I wanna disable WMM but I noticed that it will limit all wifi to 54Mbps...Help is appreciated!