I found that using origin_doc.origin_field as an option in the custom field triggers the fetch properly except for longtext. Is there any way to overcome this, or is it a bug when it comes to framework?
For reference, the field was within “Sales Invoice Timesheet” and fetched additional information required, probably on a refresh trigger, but “save” has done the job
Also (barely) visible is the timesheet note field, which is a longtext field that has the same option that doesn’t work
