Fixup of #7381 (#7401)

Fixup of commit 9c0fc8fc69

plugins/ZynAddSubFx/ZynAddSubFx.cpp

@@ -142,6 +142,11 @@ ZynAddSubFxInstrument::ZynAddSubFxInstrument(
 
 	connect( instrumentTrack()->pitchRangeModel(), SIGNAL( dataChanged() ),
 			this, SLOT( updatePitchRange() ), Qt::DirectConnection );
+
+	// ZynAddSubFX's internal value that LMMS's FREQ knob controls
+	// isn't set properly when the instrument is first loaded in,
+	// and doesn't update until the FREQ knob is moved
+	updateFilterFreq();
 }