That would not be normal, no!

Unless anyone can confirm Im wrong, i would imagine the rear screen, like the front is structural, therefore a loose screen is a bit of a safety issue.

Before panicking and ringing autoglass, Im sure some oofers on here with all their contacts can advise the best recourse.

But one way or the other, that screen needs re-bonding. Never heard of this being an issue before.

yes, a lot of the stiffness in the bodyshell comes from the screens - and f course, they need to be well attached.