Not Getting Full speeds on the R3

[BL4CK OPS V3TRN]

First my set up is as follows -   SKY Fibre  300 / 40 . I don't use the Sky provided router I have an Asus RT-AX 88U Pro wired to the ONT .  My R3 is Wired to Asus router ,  all wifi devices are going through the Asus router which is much more superior than the R3 for Wifi .  The only things attached to the R3 is the Xbox wired .

My congestion control on the R3 is 100/100 always , so not throttling the R3 at all .  Speed through the Asus Via WIFI are very close to the 300/40 I am paying for .  

However when I check the speed on the R3 it shows 95/40 wired . Same if I check speeds through the R3 via WiFI on my phone . Also when I check the speed via the Xbox which is wired to the R3 it shows 95/40 . When downloading on the Xbox the max is 95 in terms of performance .  I have no congestion control set up on the Asus , only changes for default settings are putting the R3 into DMZ

Smartboost is on but I have done tests with it on and off with no difference .

Any guidance would be appreciated .. 

[Netduma Fraser]

Sounds like the ethernet cable connecting the R3 to the Asus is the limiting factor, switch it out for another and test again. Also having devices upstream may impact the speed you get for the Xbox, not that it needs a lot of speed for gaming