Cauldron filled only 1/3 full cannot fill an empty water bottle

Water bottle won't fill up when click cauldron with water but the cauldron water will decrease
my phone is samsung galaxy V

Cauldron's filled 2/3rd or full can be used to fill an empty water bottle, but for some reason, some cauldrons (possibly those filled 1/3 full by rain water but not by bottles of water?) can't.