Laggy Arena Matches From UK to US

At launch, I first fired up H5 in Team Arena and I was amazed at how lag free the game felt and I assumed that the people I was playing with must be also be from the UK or at least somewhere else in Europe as it felt like I was playing the game on LAN! I kept playing for the next few days and I started getting paired up with people in America and to my surprise the games had a very acceptable ping and I was not feeling like I had a major disadvantage playing with people thousands of miles away I was blown away with the dedicated servers 343i has integrated into matchmaking and I was not worried in the slightest that this would change as I climbed the ranks.

Now, I have recently got to Onyx in Slayer, Free for All and now stuck on Diamond 6 in Team Arena every match that I’ve had for the past couple of days at this rank is a noticeably laggier match than the games I mentioned previously it feels like a bad host on H3 I can see Spartans lagging around corners and I don’t get perfect kills anymore … yet when I play Big Team (I’m Unranked in Big Team) the game feels lagfree again.

First off has anyone in Europe or the UK experienced this as they have progressed up ranks? I play alone quite late at night and I think I might be connecting to US servers as there’s not many people online with my rank nearby however I also remember reading something about 343 changing the parameters for ping in matchmaking and maybe this has affected my gameplay.

P.S Before you ask I have checked my connection and NAT everything seems fine 106mb/s down and 7mb/s upload.

Thanks