if they ran out of fuel shouldn't they crash? It's as if someone landed them exactly where they were supposed to land.
The Gerbera is smaller, and much, much lighter than the Geraniums.
Ukrainian specialists that catalogue and study Russian drones, claim the Gerbera has a wingspan of about 2.5 meters, and that it weighs around 20-50 kilograms. It's powered by a small pusher engine that can be bought in any hobby shop, while its construction is mostly foam/plastic around plywood formers.
Contrast this to the Geran-2 or Geran-3, which has a 3.5 meter wingspan, and a weight of 250 kilograms and 350 kilograms respectively.
The Gerbera is basically a large model airplane, like children make in high school.
It's simultaneously quite big and very light. After hundreds of uses in Ukraine, there is tons of photo proof of them landing largely unharmed, in the same way they landed in Polish fields.
So Velund's idea that the Ukrainian's could be gathering them and fixing them up is quite reasonable.
It depends of flight controller firmware, and, probably, configuration "what to do if engine stalls".
Given that we are discussing a medium sized KAMIKAZE drone, I don't think the normal fail-safe or return-to-base logic applies.
This is not a big reconnaissance drone with an expensive payload, that you need to be able to land safely if you lose control.
In fact, the Geran-2/3 and Gerbera probably don't possess any safe way of landing at all.
Probably once control is lost, the drone continues flying along the last known GPS waypoints.
If GPS is spoofed, it may switch to inertial navigation (have no idea if the German's possess suitable equipment for this).
If GPS and INS are both f*cked - I think the drone will simply continue to fly straight until it runs out of fuel and crashes.