RunForth App not logging distance/map? (Read 26 times)

I've been using my Iphone 5s with the Run Forth app to track all of my trail runs.  The app has always functioned well until about 3 weeks ago (phone software upgrade?). Now the app will track my start time and duration/time and starts to show distance and the map but seems to discontinue distance once the phone goes to sleep.  It never did this in the past, even once asleep the phone tracked my distance and map accurately.  At the end of my run I would wake the phone and the app would populate all the data.  Now at the end of my run the phone only populates distance and map to the point where I assume the phone went to sleep.

I 've tried logging out and back into the app, didn't work.  I tried uninstalling/installing the app again, also didn't work.  I suspect there is something in the phone/GPS function that is not working?  I've spent some time looking at these menus in the phone but can't find anything that would solve the problem.

I do a lot of "pioneering" when I run, so like to know how far I've gone and have a map to study later.

Any ideas?

Thanks

BJS