"Calling business methods marked with the @Remove annotation signifies a desire by the client to end the session".
Or, more simply, @Remove methods must the last transactional methods invoked because the container is at liberty to complete the transaction after invoking them.
It looks like GF did exactly that so your next invocation failed due to lack of a transactional context in which to execute.
Are you expecting different behaviour from an @Remove method?
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