FlexForms do not get initialized with default values
I was using this extension to migrate from https://extensions.typo3.org/extension/bootstrap_grids to https://extensions.typo3.org/extension/container_elements
Both of which depend on FlexForms. In many cases the defaults are fine. But I still had to open each container manually and change one value of the flexform away from the default and then back to the default in order to have the default values saved to the DB such that the output worked.