Have nullable types been changed?

var client = clients.Find(c => c?.id == id);
if (client is null)
    return Button.None;

return client.inputQueue.Dequeue();

var client = clients.Find(c => c?.id == id);
if (client is null)
    return Button.None;

return client.inputQueue.Dequeue();

this code should work since the null check should make client non nullable after but it doesn't. Client is still a nullable type after the check.

Have nullable types been changed? - C#