Possible bug Cornerstone ex ogerpon?

I just lose to a Gholdengo ex deck. My opponent Benched a Fez, a radiant greninja a togekiss and another ghold ex. So Gholdengo has an ability and my ogerpon negates attacks by pokemon that have one. Literally went through that with a common attack. My opponent didnt use canceling cologne neither had some effect that blocked the ability. This ended after my opponent killed other pokemon in my bench and he was missing 2 prizes. So I being confident left the mask alone. Did someone had this issue? Were can I report this? Unfortunately didnt take screenshots of the battle log. Thanks in advance.