Hi @KZChan, thank you for reporting this issue. I think I fixed the problem already, but I need to do some more tests. It should be fixed in the upcoming bugfix release end of this week.
Same goes for mass creeps as well. Due to the effect of the withered, sometimes one of them stay way too back from the pack. But as soon as the second from the last passes the last tile, the one who's stuck within the effects of my Gib, Withered and Frozen teleports as well.
Yes, that's really my bad :-/ I missed to recycle my creep histories when putting them back to the shared object pool! I did several tests and everything seems fine now and will be fixed in 0.8.4.