Hmm, it seems I misunderstood the OP here. It looks like he's using the nav 1 radio for ILS approach, while I thought he was using the KNS 81. I haven't had any problems with ILS approach using any other equipment aside from the KNS 81, so I don't have the same problem.
@kityatyi my advice, if you haven't tried it yet, is if you have the PMS 750, uninstall that and try the ILS approaches again. Maybe try uninstalling the KLN 90, too. The PMS 750 in particular has caused me problems at least once in the past, even when I don't have it loaded into the plane. Another thing to try, if you use Navigraph navdata, would be uninstalling and reinstalling the navdata.