Hi Marty,
I don't use Apple devices so I don't know what the App versions are, but the original iPhone App
(that I tested on my wife's iPhone 4S) did not allow changes to the parameters to be saved.
A newer version of the App was released which did allow changes to be saved:
SmartMeter App (iOS) for iPhones (version 5 or higher) and iPads:
Search GoldenMotor from App Store of Apple, then install it. (Last Updated on 16/5/2019)
In your previous post you only stated what versions of the iOS you were using not what the version of the App, which is why I asked the obvious question.
I presume that only the most recent GM App is currently available on the App Store, but I don't know whether it completely replaces or simply updates earlier versions that might have been already installed.
If it updates, instead of removing the old App and performing a clean install, this could cause the parameter saving problem to remain.
We have had Android users with a similar problem where a previously downloaded App had been reloaded from the download folder instead of the newly downloaded version.
As I said before, I don't use Apple devices, so I am not familiar with their App installation process.
Alan