Missing attachments when copying a page with subpages to another collective

[janbaum]

Describe the bug
although the .attachments.{ID} got coppied allong, the pages in the new collective can't resolve them: "Failed to load .attachments.10179099/{FILENAME}"

To Reproduce
Steps to reproduce the behavior: create a page with subpages

1. paste some attachment in subpage
   

2. copy page folder in files app from one collective to another
   

3. go to new collective
   

4. see attachments missing in collective app
   

Expected behavior
Show the attachment, just as in the original collective

Maybe this is known already, if so fell free to close this!