It looks to me that TLHelpConnector (unit LazHelpCHM) creates the internal FConnection in TLHelpConnectonr.ShowHelp, but does not destroy it any more.Yeah, it works. Thanks.
It helps for me to add this destructor:
destructor TLHelpConnector.Destroy; begin FConnection.Free; inherited; end;
Please modify LazHelpCHM this way, recompile the lhelpcontrolpkg and test. If it works for you, too, I'll apply this to trunk.