Did you adjust the scale when exporting the model originally? Make note that standard uu (unreal units) are actually centimeters.
My work flow is usually into and from 3DSMax, which when importing into 3DS allows you to change the scale from whatever its from into Centimeters (Unreal Units).
Then when you export ensure that you set your units are set to Centimeters. If you forget, and you drop the model in and it is incredibly small, I think the Feet to Centimeter scale value is something like 30.48. Someone feel free to correct me if that’s wrong.
I’m not quite sure I understand why when the model scaled up your pawn scaled up too - is your model a static mesh, if so scaling it should not affect the scale of your pawn.