TryActivateAbilityByClass triggers ability twice from the server side

Hi everyone!
I was following this tutorial, the only difference for me is - I need it to work in multiplayer - so I set Component Replicates to True for the Ability System.
I write a text when I cast a fireball and when TryActivateAbilityByClass returns a value:


In the blueprint for GameplayAbility I write a text when the event ActivateAbility is triggered:

When I cast a fireball from the server side - it works just fine, but when I am trying to cast it from the client side, this happens:

For some reason, the event ActivateAbility is triggered twice - both from client and server side. What am I doing wrong here? Thank you very much in advance!

The servers authoritative proxy (copy of your character) needs to have the ability too. So server applies the ability and replicates it to you and all simulated copies of you.