If you are seeing 32bit PC modules in 64bit SONAR, edit
HKEY_CURRENT_USER\Software\Cakewalk Music Software\SONAR\Cakewalk VST X64\VSTInternalPath and make sure there is only one path to the 64bit modules, this is what the default entry looks like

Once the paths are corrected, if the problem persists after a VST rescan, run a VST reset.