Add different setUser call.

app/Repositories/Budget/AvailableBudgetRepository.php

@@ -27,6 +27,7 @@ use Carbon\Carbon;
 use FireflyIII\Models\AvailableBudget;
 use FireflyIII\Models\TransactionCurrency;
 use FireflyIII\User;
+use Illuminate\Contracts\Auth\Authenticatable;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Support\Collection;
 
@@ -220,11 +221,13 @@ class AvailableBudgetRepository implements AvailableBudgetRepositoryInterface
     }
 
     /**
-     * @param  User  $user
+     * @param  User|Authenticatable|null  $user
      */
-    public function setUser(User $user): void
+    public function setUser(User|Authenticatable|null $user): void
     {
-        $this->user = $user;
+        if(null !== $user) {
+            $this->user = $user;
+        }
     }
 
     /**