Advanced Custom Fields > acf-json filenames

In case anyone else has wondered why acf-json files might be suddenly stored in different filenames:

If the the plugin is activated together with the advanced custom fields plugin, it’s interfering with acf’s local json filenames (if the theme is using this feature).

The file name for acf’s local json files is using underscores e.g. “group_{fieldkey}.json”. With better images activated, the format changes to “group-{fieldkey}.json”.

This causes some unwanted side effects (the .json file might be created twice, instead of being overwritten) that can prevent changes in field groups being shown in the backend.