Warlords decree keystone is bugged

the keystone thunder lords decree cannot be used more than once regardless of how many people use it. So say 4 people have that passive, that means 3 people will not be able to use it for 3 seconds if one person has proc'd it. This basically means 3 people every 30 seconds will not have a keystone. Can this be fixed please? I think it's really cool.