Hi ,

so far, I remember when you create the image in the database you have to specify the width example: (pic 2021-05-06_15-25-28.jpg)

Later when you import the database in unity as you already mentioned you could also specify the width. My understanding here is that the ratio between the width and length is already calculated in the database of the image target and it is fixed. So that when you set the one value now in unity and unity I will automatically adapt the second value. (picture 2021-05-06_15-31-57.jpg)

Therefore , I believe this lead here in your case to the fixed ratio.

Another point is that the scale / dimension of the model are not correctly displayed – so at least unity does not use  the correct blender dimensions. So when we import e.g. an simple model form blender mostly I have some difference between the shown scale (in Unity transform component)  and the model dimensions. (show in the next picture)

So seems that the transformation scale is different from the blender dimension scale (the reals model outline) . So when I check the model then in blender I see this difference.

Hello Ronald!

Thank you so much for taking the time to answer! Yes, my problem is exactly the fixed ratio. But isn't there a way to fix it? 

The dimension of my model are correct in Unity as well. I checked it ;-)

Thanks for the feedback!

to be sure that I understand the issue correctly.

Is you model scaled in all x,y,z incorrectly. -> but always the same scale factor is used . Example your model is cuboid with x,y,z (1,2,3) and the shown display is scaled by factor x ... e.g. x=0.5 - and displayed is the cuboid with x,y,z (0.5,1,1.5). What is the applied wrong scale factor then in your case?

or your model e.g. here the cuboid is shown in one direction correct but incorrectly in other direction  e.g. x,y,z (1,1,3) - here incorrect scaling in y direction. What is the wrong scale factor in this case?

Thanks!