It works now.
There was a bug with projectiles during spawn, but this is not the topic.
Error:
ArgumentException: An item with the same key has already been added. Key: PunAssaultRifleProjectile(Clone) (UnityEngine.GameObject)
System.Collections.Generic.Dictionary`2[TKey,TValue].TryInsert (TKey key, TValue value, System.Collections.Generic.InsertionBehavior behavior) (at <44afb4564e9347cf99a1865351ea8f4a>:0)
System.Collections.Generic.Dictionary`2[TKey,TValue].Add (TKey key, TValue value) (at <44afb4564e9347cf99a1865351ea8f4a>:0)
Opsive.UltimateCharacterController.AddOns.Multiplayer.PhotonPun.Game.PunObjectPool.NetworkSpawnInternal (UnityEngine.GameObject original, UnityEngine.GameObject instanceObject, System.Boolean sceneObject) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Opsive/UltimateCharacterController/Add-Ons/Multiplayer/PhotonPUN/Scripts/Game/PunObjectPool.cs:119)
Opsive.UltimateCharacterController.Networking.Game.NetworkObjectPool.NetworkSpawn (UnityEngine.GameObject original, UnityEngine.GameObject instanceObject, System.Boolean sceneObject) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Opsive/UltimateCharacterController/Scripts/Networking/NetworkObjectPool.cs:53)
Opsive.UltimateCharacterController.Items.Actions.ShootableWeapon.ProjectileFire (System.Single strength) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Opsive/UltimateCharacterController/Scripts/Items/Actions/ShootableWeapon.cs:872)
Opsive.UltimateCharacterController.Items.Actions.ShootableWeapon.Fire (System.Single strength) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Opsive/UltimateCharacterController/Scripts/Items/Actions/ShootableWeapon.cs:779)
_Game.Infrastructure.CodeBase.PhotonPun.PunCharacterCustom.FireRPC (System.Int32 slotID, System.Int32 actionID, System.Single strength) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/_Game/Infrastructure/CodeBase/PhotonPun/PunCharacterCustom.cs:571)
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <44afb4564e9347cf99a1865351ea8f4a>:0)
Rethrow as TargetInvocationException: Exception has been thrown by the target of an invocation.
System.Reflection.MonoMethod.Invoke (System.Object obj, System.Reflection.BindingFlags invokeAttr, System.Reflection.Binder binder, System.Object[] parameters, System.Globalization.CultureInfo culture) (at <44afb4564e9347cf99a1865351ea8f4a>:0)
System.Reflection.MethodBase.Invoke (System.Object obj, System.Object[] parameters) (at <44afb4564e9347cf99a1865351ea8f4a>:0)
Photon.Pun.PhotonNetwork.ExecuteRpc (ExitGames.Client.Photon.Hashtable rpcData, Photon.Realtime.Player sender) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Photon/PhotonUnityNetworking/Code/PhotonNetworkPart.cs:553)
Photon.Pun.PhotonNetwork.OnEvent (ExitGames.Client.Photon.EventData photonEvent) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Photon/PhotonUnityNetworking/Code/PhotonNetworkPart.cs:2201)
Photon.Realtime.LoadBalancingClient.OnEvent (ExitGames.Client.Photon.EventData photonEvent) (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Photon/PhotonRealtime/Code/LoadBalancingClient.cs:3353)
ExitGames.Client.Photon.PeerBase.DeserializeMessageAndCallback (ExitGames.Client.Photon.StreamBuffer stream) (at D:/Dev/Work/photon-dotnet-sdk/PhotonDotNet/PeerBase.cs:899)
ExitGames.Client.Photon.EnetPeer.DispatchIncomingCommands () (at D:/Dev/Work/photon-dotnet-sdk/PhotonDotNet/EnetPeer.cs:565)
ExitGames.Client.Photon.PhotonPeer.DispatchIncomingCommands () (at D:/Dev/Work/photon-dotnet-sdk/PhotonDotNet/PhotonPeer.cs:1771)
Photon.Pun.PhotonHandler.Dispatch () (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Photon/PhotonUnityNetworking/Code/PhotonHandler.cs:222)
Rethrow as AggregateException: Caught 1 exception(s) in methods called by DispatchIncomingCommands(). Rethrowing first only (see above).
Photon.Pun.PhotonHandler.Dispatch () (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Photon/PhotonUnityNetworking/Code/PhotonHandler.cs:240)
Photon.Pun.PhotonHandler.FixedUpdate () (at D:/MyProjects/MyGitHUB/Playzzy/Top-Down-Coop/Assets/Photon/PhotonUnityNetworking/Code/PhotonHandler.cs:145)