In fact, DavidsMusic is correct, as far as the chord track playing back is concerned (I was about to reply the same thing as you, Steve, but I double-checked it first, and was indeed surprised to notice that the last chord cut off at the end of the next bar.)
On further exploration, this only happens with the final chord, so, the best I can come up with for now is to add an extra chord two bars later (could be the same chord, of course). (no promises, but I’ll see if there is now any way to mute that unwanted final chord)…
Yes 
… Just make sure that the final chord is undefined.
So, let’s start again…
Insert an extra chord, without defining it (so it is still “X”) at the place where you want your final audible chord to stop.