Richards comments lead me to investigate further, so I put the phone in the cradle and gave it a good wiggle and bump, I was able under certain circumstances able to wiggle the phone free. This was not any fault with the holder, it was that my phone was a just a bit narrow. If it had been 5mm wider there would have been no problem and the phone would have been held firm and solid.
As my phone wasn't 5mm wider I had to make a few creative changes. I took and old plastic phone holder and made corner pieces to hold the phone in place and also added some small foam pieces to give a bit of a cushion. It is now rock solid and I am confident that the phone will be held firmly in place.
Here are some photos to illustrate. Also some photos of the Ram ball adaptor for Martin.
Finished article with the phone in place
Here are the breakdown pictures of the ball adaptor
I looked at Quadlock and you had to buy a new case with a change of phone.
This solution was not about a phone holder, I had a perfectly good phone holder. This was about wireless charging.
The Quadlock solution to wireless charging is very expensive.