Thanks for following up Harald.
Is the region gray in the resulting packed texture? Could you please post a screenshot of the resulting packed texture as well as the source texture?
What is weird is that the face region is inside the texture and displayed properly, yet there is a a grey area somewhere else. Also, by looking at the texture, I noticed that many arms regions were weird. I tried displaying some and they are randomly cut too. But just by looking at the repacked texture as a whole one can see that something is odd.
Maybe the non-power-of-two is causing problems here, although the Texture Import settings look correct. Could you test what happens when you enable "Power of two" in the Spine export settings?
Ticking "power of 2" at export is solving the grey area issue and actually showing that the face region is duplicated on the texture. But as you can see there is still some random cuts. I checked my exported texture and the face region is not appearing twice there.
