Thank you so much for your answers, both of you, there was something wrong with my shadow at the base of the object.
I noticed that when I uploaded the object without the shadow, it layed flat and otherwise was elevated. I had been trying to resolve this for hours but didn't think about checking that.
But it is the first time I add a shadow to an object so I'm a huge noob.
Thank you for taking the time to help, you're so knowledgeable, I always see your answers in forums and have been helped by them many times already reading other ppl's issues and your answers.
I think it was exactly the bounding box issue.