I can confirm that I am using the correct view mode. After further investigation, this appears to be happening with any field in Layout Builder. In Drupal\layout_builder\Plugin\Block\FieldBlock::blockAccess, the selected field's isEmpty() method is checked, and if true, access to the block is forbidden. There appears to be an issue for the Drupal project to try to add a setting to allow the field to display, even if empty. It would be nice OfficeHoursItemList::isEmpty() returned false if show_empty is checked, but I can understand how that would be messy to implement.
In order to replicate, all the hours must empty on the entity.
Without Layout Builder.
With Layout Builder
jeremyvii → created an issue.
jeremyvii → created an issue.
jeremyvii → created an issue.
jeremyvii → created an issue.
When applying the patch from #12, Image and Video Media entities worked as expected, while Audio File and Document Media entities did not. I could view Audio File and Document Media entities via the media/{view}/{id}/view path, but I could not download these media items via media/{view}/{id} or media/{id}.
This patch worked. Thanks!