Update

The Amarok was in for servicing today and to get the cruise control checked out. The battery was OK and well off the point of needing replacing. There were no faults logged re the stop-start.

The fault logs however confirmed "faults in system for cruise operation". The logged faults relate to a software deviation which is known to Volkswagen who are currently working on a software upgrade. This is not available at the moment, but the dealer who did the service and diagnostics said they would be in touch when the revised software has been rolled out.

The dealer cleared the logged faults and the cruise control is working normally again. The dealer did say the issue may come back, but once the upgrade is available from VW, that should correct it permanently

I posted this just in case anyone else experiences issues with their cruse control