Hi Walter,
Based on your description, it sounds like Autoclose previously working, right?
Out of box Change Order Status detail 'Make Change Order Active?' is Yes. If you have it back to Yes, does Autoclose work?
The Autoclose not working could cause by many reasons. One of reasons is incomplete workflow tasks. Verify the Change Order supposed to Autoclose whether it has incomplete workflow tasks. Also, check the stdlog of the timeframe any errors when the Autoclose should execute.
Please let us know your finding.
Regards,
Derek