MC-111286 is not a bug. The reason that short 'flights' do not count is due to jumping. If it would count any time the player is in the air, it would count jumping too.
It does not. MC-99958 Describes that it only updates when you hit the ground in survival mode, while this reports that the values of falling from different heights does sometimes not result in a different value for the stat.fallOneCm, while it should.
MC-111286 is not a bug. The reason that short 'flights' do not count is due to jumping. If it would count any time the player is in the air, it would count jumping too.