GPX/TCX files on third party app or as a file on iPhone, will not load into the iphone Connect app, but will load into all other apps. I get an 'Ooops! Something went wrong loading your course.' I've deleted and renewed the app. How can I fix t

I want to be able to plot a route or accept one from else where when I'm not at home.  

I want to be able to load a GPX file from my iPhone onto the iPhone Connect app, so that I then can use it on my Edge device.

I have tried the GPX and TCX files stored in Notes, Email and Files.  They all work on a number of other mapping/fitness apps on my iPhone,

but not on Connect.

It immediately tells me 'Oops! Something went wrong loading your course.'

I've watched YouTube tutorials that show the process working.  So I know that I'm not missing any steps in the 'process'.

I have nothing else to try...

Can anyone help?