Xbox One X & GOW5 - lag. What can I try?

[#1]

So I got myself Plusnet fibre broadband (great btw, thank you) and a Xbox One X about 6 weeks ago. I only play Gears Of War 5 online. The problem I have is that 90% of my games are very laggy, which is kinda soul destroying. I was wondering if there were any settings in my router I could check that could maybe improve lag?

Router: Plusnet Hub One

NAT: Open

Connection: Wired

D/L Speed: 35.32Mbps

U/L Speed 9.11 Mbps

Packet loss: 0

MTU: 1480

Latency: 30ms

Xbox multiplayer check says there are no problems with my connection for multiplayer.

Would really appreciate any help. Thanks.

[#2]

It may be worth trying a slightly lower MTU - say 1472, or even as low as 1420. It may make no difference, but unexplained lag is often a sign of packet fragmentation - to confirm that diagnosis (or to find any other cause) you really have to use Wireshark or some other tool to examine the traffic.