That's easy, and simple...3. Is there anything else I can do to avoid this from happening?
Two things - and both have already been mentioned previously in this thread.
1. NEVER power on the Drone close to ferrous metal, to include sitting on concrete with metal rebar reinforcement... this will negatively affect the compass.
2. ALWAYS wait for an adequate GPS lock - at least 9-10 satellites, and wait for the app to announce 'home point acquired'... otherwise the Drone will not know where home point is.
Post your logs for crissakes!