Objects messed up when I re-open the file I'm not an expert in Blender (and sorry for my english), so I'm really having troubles with an issue I'll describe here:
I've modeled a body with every part as a different object.

I want to sculpt it now, so I applied the scale of each body part.

The problem is that now, if I close the file and then I re-open it, I find every object completely messed up in scale, location, ecc..
I also tried to apply every transformation but the result is the same.

What am I doing wrong?
I am using Blender 2.91.2
Thank you
Because you have keyframed Location, Rotation and Scale values.
To see the issue you don't have to reopen file, just move on Timeline to another frame.
After Apply Ctrl+A All Transforms you have to set keyframes again I. Yellow color indicates keyframed value, orange edited/unsaved a change.
What is happening here? When you apply transforms they became to zero and  1 for scale, but unsaved keyframes remember saved value and when you move on timeline or reopen file, they &quot;jump&quot; back, so they are used like twice now.