It should work. In version 5.5. of ACF it started using term meta instead of options for storing term custom fields. The update process should convert the data in the database. Make sure you follow the upgrade process carefully https://www.advancedcustomfields.com/resources/upgrading-v4-v5/. If you have any problems after the upgrade submit a support ticket https://support.advancedcustomfields.com/new-ticket/
