Proper workflow with Revit (and Revit LT), how to export / reimport buildings without losing all materials

We use Revit and Revit LT in office.
Since Revit LT can’t have plugins, we can’t use Twinmotion plugin on those computers. So I thought the best way is to export as OBJ and import it in Twinmotion.
This works perfectly well, until you have to change something.
But once you change something and export the building we’re getting two issues.
First, sometimes after reloading the new model, it looses all of the assigned materials. It’s pretty impossible to work with having to reapply everything to an entire building.
Second issues, sometimes, the new object gets imported on completely wrong place, like 50m away from where it should be. Without moving it in Revit.

Currently I’m having both issues in the weirdest way.
I have to add some windows on the building, but first new model got reimported to a completely wrong location (while maintaining materials), and then after trying to solve that new model gets imported to proper location, but loses all of the materials.

Any idea what I’m doing wrong, and it this approach completely wrong from the start?
Thanks in advance!

EDIT: I have no idea what’s going on. I tried exporting / importing once more, with the same settings, the same object, nothing moved. And now it came into the correct position, and kept all of the materials.