The animation is 23 frames, 24fps, which I have set up in marmoset. The animation loops in Maya and I checked it in our school 3D engine and it loops. But in marmoset it studders on the last frame which makes it not loop (and it looks wonky) :( Does anyone know why?
This is likely an interpolation issue. In Toolbag 4 we've added a loop option for animated meshes that may resolve this. I would suggest downloading the free trial and giving it a go. https://marmoset.co/toolbag/#dltoolbag