I cannot attach any screenshot but I realizet multiple time following:
I play agains death mark level 5 opponent and put my crusader and put quintesence on it, so it is untargetable. Sometimes it is became 2/2 inmortal skeleton but I lose his skill. I tried to find what happened, sometimes opponent has boneyard but it couldn't influence (I hope) but AI didn't play any card for damage.
It appear in 1.27 version.