Steps to reproduce

1. Use Ibexa Experience 4.6.3.
2. Edit the landing page content type
3. Edit the ezlandingpage field definition, make the banner block unavailable, and only one of the layouts available.
4. Save changes.
5. Execute the migration from the attached file.
6. Edit the landing page content type and check the settings of the ezlandingpage field.

Expected result:
banner block is available and only the previously selected layout is available.
Actual result:
banner block is available as expected, but all layouts are available now.