Sorry for bumping into an old conversation. Have you tried checking the bone positions of the model? Sometimes the position of the bones can affect how the model appears in the game.
You also mentioned that your ""pose"" meshes are in a different place than your ""armature"" positions. It might be worth taking a closer look at this and ensuring everything is aligned correctly. If you look for alternatives, there are many excellent games on this list
https://joywallet.com/article/best-money-making-apps/. I hope that helps!