We had alot of problems with this, finally a combination of several factors worked out. Set your default scene to metric with scale of .01… So when you load your scene it is already set properly… ALSO when you export set your fbx export to .01 ← this turned out to be the correct scale for export… Everyone kept saying that it had to be 100 or 1… This was not the case. Now we have absolutely no problems… Just make sure your dimensions are the actual size you want them in the N tab and export… Due to the radical scale issues we have had I hope this works for you. But like I said it works perfect for us.