?
Keep in mind that Timeout (or cancellation in general) is not guaranteed, and requires that the task (generally, an operation) properly check for a cancellation token. For example, an operation that simply did a Thread.Sleep for 1000 seconds could not be timed out after 10 seconds.
In a case of a stuck execution, restarting the service is the best way to clear things.
So, we'd need more context to identify if it's a bug in the operation, or simply something that isn't support.