Speed at router (RT-AX88U Pro) is as expected, speed at all computers and phones is slow

[WeyldFalcon]

1. My router (RT-AX88U Pro) clocks my internet connection speed at around 1.4Gbps
2. My 2 wired desktops and my laptop clock around .45Gbps
3. My cell phone on wifi clocks around .62Gbps (not surprising)
4. I have 1G NICs on all my hardware except my main computer which is a 2.5G
5. I am using Cat6 cable
6. I turned off QoS
7. I am running Firmware version 3.0.0.6.102_33308
8. If I run speed test on 3 systems (2 desktops and phone) I can get the Download Bandwidth monitor to jump up to 1.4Gbps but not on a single machine.
9. What could be causing this throttling?
10. Follow-up question why are my wired machines getting slower downloads than my wireless cellphone?

[jzchen]

What is the speed you get on the 2.5 Gbps enabled main computer?

[WeyldFalcon]

was getting 450Mbps this afternoon but I just got 530Mbps now, still not 1.4Gbps but a little better than before.

[jzchen]

If there're no other clients connected at the same time to "drain" bandwidth that does seem quite slow, actually even with.  If it's a Windows PC you can try uninstalling and reinstalling the Ethernet driver(s) and try again?

[WeyldFalcon]

No other clients connected at time of testing other than when I was testing running speed test on 3 machines to see if I could hit 1.4Gbps with multiple machines. I have tried 3 different machines each with different network cards and one with 2 different network cards (my main computer has a 1G and 2.5G NIC. Is there a setting on the router that could cause this? All NICs have the newest drivers I can find. I also tested wifi on my main computer this morning and same 530Mbps, it really feels like there is some cap the router is applying because clearly it can go higher but none of the systems seem to want to go higher.