So I think I read that spatial visualization is in a different part of the brain from visual imagery. For example, I have really good spatial memory. I can imagine my childhood home and construct the spatial layout nearly perfectly in my brain (I don't really see it but it's there) but I can't imagine the face of a loved one who I haven't seen in a while other than to tell myself something like, "they're short, they have brown hair, etc". I can easily remember how to get from point a to point b as I'm almost mapping it out in my head, but I can't picture an apple. That may account for what you're experiencing.

So I think I read that spatial visualization is in a different part of the brain from visual imagery. For example, I have really good spatial memory. I can imagine my childhood home and construct the spatial layout nearly perfectly in my brain (I don't really see it but it's there) but I can't imagine the face of a loved one who I haven't seen in a while other than to tell myself something like, "they're short, they have brown hair, etc". I can easily remember how to get from point a to point b as I'm almost mapping it out in my head, but I can't picture an apple. That may account for what you're experiencing.