Should the remote be connected to KPA when upgrading OS?

Recently I updated my KPA OS to shiny new 5.1 without Remote connected to it and today I noticed a few strange things. Remote lights flash sometimes like they got disconnected for a millisecond. And sometimes I get a high frequency fizz even when guitar volume turned down to zero. Could it all happen because Remote firmware is not updated and how to update it since KPA itself has the latest firmware and possibly won't update itself to the same version again?