AshPort
150+ Star Club
this is very similar to how it started for me, i now do i video at a time, then restart etc, managed to complete the event tooThis is a little different. That's what I thought at first, but I started definitely waiting until the planes were fueled and had taken off. Then I even landed some other guest planes, 1 at a time, serviced them and let them take off. Then I went visiting or switched to another app, and when I came back the same 2 original guest planes were back.
I'm not 100% sure of my memory of this but I think I even force-closed the game, re-opened it, and the 2 planes were back. At that point once I sent them on their way they stayed gone.
During the time with the reappearing guest planes the other actions I took in the game did take effect as normal. I was not losing progress in general, I just had 2 reappearing guest planes. I got my final 2 rocket sleighs and built hangars for them; those stuck around.
A few hours later on I did have some crashes that lost progress. I completed flights, the game crashed, I came back and had to complete those flights again. The worst lost for me was the 8 greenies from the happyxmas bonus.