Enemy's being untargetable after wooglets/zhonyas!!!???.....

as Shaco i pop out nearly kill and they wooglet/zhonya to survive... but before its effect ends i plant a shaco box to get them.. but when they come out it does nothing .......

like in 2 games of hexakill they wooglets to live i put a box to get them but the exact instant it ended vlad blood pooled away and killed me, and ziggs at exact same time wooglets ended unleashed all his abilities destroying me and box and box did nothing to him....

then in aram vs ap rammus he zhonya, then exact same time ended he Q hit and unloaded and my box did nothing ......