I'm starting to wonder if this thing is wired incorrectly.

Anyone happen to know where I can find a wiring diagram or schematics for this machine?  XY600GKE also sold under the following names:  Chironex, Komodo, Groundpounder.... ect.

Heck, I couldn't even find the owners manual.

[2015 Z Force 800 53/Trail EPS]

Might use a CFM engine but it's not made by them so..that's going to be tricky.

It's made by XY Powersports or Xingyang, I can locate manuals and wiring diagrams for the XY1100GK. Just nothing on the XY600GKE is all.

The issue with removing the speed sensor (which when tested, passes), allows the machine to operating as intended makes it even odder. Could there be a child safety, seatbelt safety, or 4x4 L that prevents the machine from moving faster than 15 mph when switched? I mean the manual you provided has the exact engine, but the wiring is slightly different.

[2015 Z Force 800 53/Trail EPS]

Yes, there can be..especially in 4x4-Low range or in a diff-loc state. Many have that.