Admin item edit doesn't work properly after saving changes the first time

[atarix83]

Describe the bug
The admin item edit functionality doesn't work properly after saving a metadata the first time

To Reproduce
Steps to reproduce the behavior:

1. with admin user go to the edit metadata page for an item
2. edit a metadata and after confirming click on save button
3. edit the same or a new metadata
4. at this point the table content disappear and is not possible to proceed with the operation

DSpace.Angular.__.Item.Edit.-.Metadata.mp4

[tdonohue]

Closing, as this is no longer reproducible in 7.5. It appears to have been fixed by #2028