No problem on my iPhone7s (4.15.02)
The link below is a recording of what what actually happens on the iPAD Pro when I import the Beta GPX to the Drive App.
I have re-installed the Garmin Drive App and gone through all the set up including syncing my data to the Garmin XT
You will see me open the Drive App 3 times then you will see me import a route using the Beta GPX file.
You will see that as soon as I “open In” the Garmin Drive App it immediately crashes.
You will also see that after this that trying to open Garmin Drive App immediately crashes every time.
Also after recording this screenshot and posting this I shut down the iPad and rebooted it.
The Garmin Drive App continues to crash after rebooting the iPad.