tied notes not working on sequencer staff

when i place a tie on a note from the sequencer staff it ignores the second note.
From the attached screenshot the 'd' on the upper clef is supposed to sustain and looks like it should to me however on playback I get the 2 stacatto notes in the second last bar then silence.
Any thoughts appreciated.
From the attached screenshot the 'd' on the upper clef is supposed to sustain and looks like it should to me however on playback I get the 2 stacatto notes in the second last bar then silence.
Any thoughts appreciated.