Sort by is_open - open ones first

app/Models/Client.php

@@ -283,6 +283,7 @@ class Client extends Model
     public function tickets()
     {
         return $this->hasMany(Ticket::class, 'client_id', 'id')
+            ->orderBy('is_open', 'desc')
             ->orderBy('created_at', 'desc');
     }