My setup is Modem > Cat7 Ethernet > Main Router > Cat7 Ethernet > Main Deco XE75 Pro Unit > Cat7 Ethernet > the 2 other Deco XE75 Pro units.

My gaming PC is connected to my main router via Cat7 Ethernet and I have no problems speed wise or ping/packets when gaming.

My other devices when connected to a Deco XE75 Pro Unit have no problems speed wise I'm getting exactly what I'd expect.

But my upstairs unit which like I said everything is backhauled via Cat7 Ethernet when I then go from that XE75 Pro unit via Cat7 Ethernet to a Xbox Series X there are now ping/packet issues with loss packets and whatnot.

If you google "TP Link Deco Mesh XE75 Pro lag when gaming" when you will find muliple people talking about the same issue and everytime TP Link's response has been to have their senior engineers contact the customer via email and I don't know how to contact them myself so I was wondering if someone from TP Links support team could see this post and have the senior engineers team contact me please and thank you!