`$users->count() > 0` does not imply `$users->first()` is non-null: $PhanTypeExpectedObjectPropAccess reported on Laravel collection items

Hi

I'm getting a weird error when fetching first element of a collection (constructed from an eloquent db model):

        $users = User::all();
        if ($user->count() > 0) {
            // @var User $user
            $user = $users->first();
            return $user->id;
        }

The error I get:

PhanTypeExpectedObjectPropAccess Expected an object instance when accessing an instance property, but saw an expression $user with type TValue|null

The @var annotation doesn't make a change...
The only thing that works is asserting (locally) the variable like this:

        $users = User::all();
        if ($user->count() > 0) {
            // @var User $user
            $user = $users->first();
            if (null === $user) {
                throw new \Exception('user is null, it should not');
            } else if (!$user instanceof User) {
                throw new \Exception('$user should be an instance of User');
            }
            return $user->id;
        }

I also tried to externalize the logic in another class to make the code shorter but it not preventing the phan error reporting ...

        $users = User::all();
        if ($user->count() > 0) {
            // @var User $user
            $user = $users->first();
            // throws an exception if variable is null or if not an instance of the provided class
            TypeAssertion::assert($user, User::class);

            return $user->id;
        }

The issue names no source file or test; start by reproducing the Laravel collection example and tracing the PhanTypeExpectedObjectPropAccess diagnostic. Verify how count() and first() are modeled, then add coverage for the reported non-null implication while preserving diagnostics for genuinely nullable values.