Bruce updated the JFiles template with this changes
Version 3.14 - 2 June 2025
Revert: Change made in 3.12 to decode \Uxxxx values early. Causes problems when embedded json strings are using \U to encode \" etc.
Added more consistent error handling - via Errortrap.
That may be the culrprit of your problem with the specific version? Worth the try I guess.