Types custom field validation does not work if editing posts with the block editor

Symptoms

When setting up Types custom fields they can be marked as required or for certain fields, such as the email field, validation is applied that the field value is of the correct type for that field.

This works well when editing posts with the Classic editor, but does not work if using the Block editor.

Required fields are not required (the post can be published anyway), and validation messages (such as “Please enter a valid email address”) are not shown.

Workaround