test case: http://codepen.io/kgcreative/pen/LZZgxG
specifying min-height: anything breaks the layout in Version 9.1.1 (11601.6.17) as well as safari for iOS.
if I specify min-height: 0, the problem goes away.
If I specify max height, or height, the min-height attribute overrides both of these.
if I remove "column-count", the problem goes away.
It seems to be specific to min-height in combination with "column-count".