So it turns out I was using a custom event “CL_AddCard” and had it set to Execute on Owning Client, but did not have it ticked as “Reliable”. Ticking the reliable box solved the problem.
So it turns out I was using a custom event “CL_AddCard” and had it set to Execute on Owning Client, but did not have it ticked as “Reliable”. Ticking the reliable box solved the problem.