The Machin MA14 stamp is from Sutton, which may have gone live on 27 June:
This 2nd class was bought at Lavender Hill Battersea a couple of months ago, so the machine has probably been fixed by now, but the huge left margin suggests that the reel was not installed correctly - or there was a software fault.
Dominic also reports:
Robert sent this picture of a Post and Go label from a Paignton Wincor machine back in May with a band of printing missing:The new Islington Office (031004) opened as planned(16th June). Yesterday the 2 machines had 1st class MA13 and 2nd Class MA12. These machines have a modification which means you have to insert each coin rather than putting the whole lot in the bowl.