Sigarda immune to grip of desolation

Karmaspender
Karmaspender Posts: 6
Opponent plays sigarda, no humans on the board. Can target it and the other creatures with grip of desolation, but nothing happens and the spelll doesn't cast. Finally drew a to the slaughter and it worked, still lost an event round because of it tho. Just fix the issue please, like sigarda wasnt busted enough lol.