The fix from this ticket (https://jira.ez.no/browse/EZP-21124) makes it so that the checkbox is saved when the editor is enabled. However, if you disable the editor and the re-enable the editor, the checkbox is lost.

To reproduce the issue, set up the same test case as https://jira.ez.no/browse/EZP-21124, save a checked checkbox when the editor is enabled, then disable the editor, then enable the editor. The checkbox will no longer be checked.