When you summon levitation with the new /effect command then you get the levitation effect but you dont levitate.
MCPE-20300
/effect levitation bug(1.0.5)
Resolved
Fixed
1
(Unassigned)
62902
Confirmed
Phone - Android - Huawei Honor (Specify in description)
7.0
1.0.5.0
1.0.5.13
Retrieved
This seems to be a feature not a bug.i just found out that you need minimum level 9 or 7 to float.