Tides of War

During this mission on the Gold Edition when clicking on the Enemy Sub on the TAC unit to plot the way point, the engine always set itself to 'all stop' ?

Ship did change its heading but it wanted to 'all stop' everytime. I completed the mission but this must be a bug on this mission.

It has to all stop first to pivot turn usually.

indeed i understand that but once it had pivoted the sub being 400Mts away remained all stopped.