Thank you for your help. I can not get it to work still. In your graphic example you have the Send Event on the first Start state, but in the written example you have it the other way around. No matter, I tried both.
I dont have an On Click in the inspector as the FSM's worked fine without it. I have some UI graphic changes on the End Turn button and they have now decided to fall over, probably due to a conflict with an attempt to install Itween as DOTween Pro wasn't co-operating. I did get Itween to work for a different matter, but it seems more than coincidence that I now have 3 exceptions on my end turn which is fitted to the canvas.
When I connect the Start to the return key it works only once.
PS I now have no errors but can not get the Return key working.