Cant Call Remove Children Function from other Blueprints

Hello,

I cant seem to call Remove Children Function from other blueprints. What i have is a uniform gridpanel and im trying to remove all childrens using Remove Children. i can call using a input from the same bp but using other bp doesnt work. I have a created a function which uses “Remove children” and the that function seems to get called since i am getting print string result. also the reference is valid. any workarounds?