Link objet data uv copy problem

I have a problem with the data transfer link.An copy uv after.

1st: when I make a uv copy without the data transfer link and after a uv pack (to pack all uvs) the uvs for the object with uv copied all exploded (like a lightmap).

To summarize after transfert uv from 1 object to another when I’ll pack the uv the copied uv explode face by face!

If I do "link object data and uv copy and pack after that, it works.

But the objects must not be mirror otherwise the link changes the rotation of the object.
What solution will I have to copy my uvs correctly and that I do not have these worries?

thanking you in advance for your help.