Being "locked out" of my gaia app!

On recent hike, I was in a valley surrounded by trees when I tried to open my gaia; it would not open, just showed a small clock face on which the hands did not move.  I assumed the app would open when I got to higher elevation with a clear view of the sky in all directions--still the app remained locked and would not open until  3 days later when I got home.  Why did my gaia lock up and refuse to open even after I got to a point where the sky was clear and no obstructions around me??

I had to do my whole 3-day trek without being able to use my gaia.  That could have been serious.  Fortunately, my companion had a different gps device and it worked.  But I would like to know why my gaia locked up and what could I have done to unlock it?