Thanks tjinc and apologises for not seeing that detail in the previous post. It seems I didnt toggle the time code on the main player first as you suggested
To get just time remaining displaying, I then used PlayDuration, BUT weirldy i needed to have PlayPosition present too in order to get a countdown without lag, which I then changed to the same colour as my background to hide.
For some reason PlayDuration on its own kept freezing. The two elements together works fine.
Thanks for your help :-)