Play count

I am having trouble getting the "Play Count" feature working ......
I use a short score for practice and I would like a repeated part at the end of it to go into a loop and go round a number of times before ending.
The normal setting is the standard two passes using Volta 1 and 2, so the usual "repeat Barline" is at the end of Volta 1.
So far so good; I get the default 2 passes of the wanted section followed by the exit / end through Volta 2.
As I am after many more passes than 2, such as 7, I set the Play Count in the measure with the Barline under Volta 1 to "7" ....
I hasten to add that the "Toggle Playback" at the top is also enabled.
When I play the score using these settings now, nothing new happens, I still get just the two original default passes, not seven.
Frustrating, especially as it actually did work once or twice to start with!
Please note that using the Play Panel's Loop feature is not an option as I want to save the result (with 7 repeats) as an MP3 file for external use.
Any ideas, please?