Do not use GetPlayerCharacter(0).
On server side this will return the first character available (ie. host player or first player alive)
On clients this will return each client’s own character. This is why it enables collision for everyone.
Instead, you need to find a way to reach the character in context, ie. the character triggering this notify. I’m not sure how this is set up, but the MeshComp pin seems promising, you can probably do MeshComp->GetOwner->CastToCharacter