deleting extra beat

hi, this is my first time using this program and mostly I have found it pretty user friendly. However, I have ended up with 5 beats in a 4-beat bar, I can see the extra beat but I can't figure out how to remove it. I have tried deleting the contents but nothing is working.

for reference it is a voice+Piano score and the bar in question has 2x crotchet triplets for voice and treble piano plus 2x minim chords on treble piano (entered as 2 voices - voice 1 is where the extra beat has appeared as a crotchet rest between the triplets), base piano has 1x minim chord + 1x crotchet triplet.

TIA