I've had this issue myself with imports from Max. I solved it by resetting the Xform, collapsing, and re-exporting. Use the Edit > Project Configuration to update your mesh. I've also had similar when importing groups from Max - ungroup and re-import to Painter.
If you are not using Max maybe there are similar actions in your software.
Replies
Have you...
3ds max - Reset Xforms?
Maya - Freeze Transforms?
I've had this issue myself with imports from Max. I solved it by resetting the Xform, collapsing, and re-exporting. Use the Edit > Project Configuration to update your mesh. I've also had similar when importing groups from Max - ungroup and re-import to Painter.
If you are not using Max maybe there are similar actions in your software.
Hope this helps!
Daf
EDIT:And I fixed that with flipping the faces. Thanks for the help!