Why did my phone's GPS receiver stop working when the plane was descending to land? Recently, I flew on an Airbus A320. I turned my Lenovo A328 Android phone into airplane mode, and then used the default Maps app to watch my position using GPS. For most of the flight it worked normally. However, at the end of the flight, at about the time the plane started to descend so as to land, the GPS position marker suddenly jumped to an obviously wrong spot. After that, it ceased to update — at least until I got out of the plane.

Is it expected behavior of a phone GPS receiver during a flight? If so, what causes it? 

It seems the plane does need GPS itself to be able to, e.g., send ADS-B data, so it doesn't seem likely that it jammed the signal. It also doesn't look like the clouds could be an obstacle for GPS signals, since after the landing the operation of my phone GPS receiver resumed (being under the clouds).

For reference, here's flightradar24 data about my flight.
A GPS needs a line of sight to (at least) 4 satellites in order to compute a position. Given that you were able to get a position during the cruise, I assume that you were close to a window and had a clear view of a part of the sky.

During the cruise, the aircraft trajectory was close to a straight line (or changing slowly), so your receiver was able to keep a line of sight to the same set of satellites. But during the approach, the trajectory was much more dynamic (lots of turns), so your receiver didn't had a constant line of sight toward the same set of satellites and "lost" them. It takes time for a receiver to "lock" on the signal of a given satellite, so the receiver it couldn't compute a position from other satellites because they were not in sight long enough.