IOS Compatibility

I recently bought the Litchi app for IOS. I have a Phantom 3 Pro running the latest firmware and working perfectly with DJI Go. With the Litchi App I get a dji_check_product_disconnect_reason error when loading the app.
I am using an Ipad Mini 2 with IOS 12.5.7.
I have tried an Ipad 9th Gen with IOS 17.6.1 and an Iphone 11 with IOS 17.6.1, all with the same error which is strange.
Litchi say they have tested with an Ipad Mini 4 and IOS 15 with no error.
I wonder if it could be a controller issue, I have a GL300B.
Before I buy a new Apple device (Mini 4) could others with a working IOS configuration please list their hardware:
Apple Hardware type -
IOS -
Controller version -
This will also be helpful for others.
Thank you.

No need for duplicate threads.

There is no solution in this thread hence my question. Not a duplicate.

A moderator has responded in the original thread.