We have a content type that uses Layout Builder as it's default display. After performing the 10.3 database updates the default display is modified to include a field block that wasn't part of the display before hand. I'm thinking this is related to the Layout Builder Expose All Field Blocks module addition.
The configuration changes made by the update:
Default layout now contains a field block that it previously didn't:
Active
10.3 ✨
Last updated
Yes,this feature is planned to move with a feature flag module as mentioned in https://www.drupal.org/project/drupal/issues/3432874 📌 Replace "Expose all fields as blocks to Layout Builder" configuration with feature flag Active .