I do not know, Hivesigner is maintained by good-karma, however, I do know that there were some issues with Ecency RPC (which hivesigner uses by default) so that could be related.
RC delegations/undelegations are instant, but when you undelegate RC from a user, you don't receive the unspent RC back, but rather your "maximum RC" increases, so it'll regenerate over time. (the previously delegated one)