Thank for all the replies so far.
I am still investigate this as it is a major issue for me, I dare not release any new code until this is resolved
CustomListView works for on newer devices, but my old ones stuck on 9.3.5 will not work.
The code has not changed and I am not doing anything funny with the code, the only thing that could have changed ( as far as I can deduce ) two weeks ago is the hosted builder!
Code was compiling and installing and running fine the week before last on all my devices.
Please help
Can anyone with an old device still running iOS 9.3.5 try the short test program for me .... in release mode. It should simply display a screen with a single box ( the listview), thanks