Wrong displayed duration when using \displayNote and \tuplet together

[tilgwullfi]

Minimal example:

{[\clef<"g2-8"> \key<0> \meter<"4/4", autoBarlines="off", autoMeasuresNum="system"> 
	\stemsUp
	\beamBegin:1
	\tuplet<"3",dispNote="/8">(
		\displayDuration<1,1,0>(a-1/12)
  		c1/12
		e/12
	)
	\beamEnd:1
]}

Another variant:

{[\clef<"g2-8"> \key<0> \meter<"4/4", autoBarlines="off", autoMeasuresNum="system"> 
	\stemsUp
	\beamBegin:1
	\displayDuration<1,1,0>(
		\tuplet<"3",dispNote="/8">(
			a-1/12
  			c1/12
			e/12
		)
	)
	\beamEnd:1
]}

Or:

{[\clef<"g2-8"> \key<0> \meter<"4/4", autoBarlines="off", autoMeasuresNum="system"> 
	\stemsUp
	\beamBegin:1
	\tuplet<"3">(
		\displayDuration<1,1,0>(a-1/12)
		c1/12
		e/12
	)
	\beamEnd:1
]}

All those lead to the same result: