Hi,
It has happened on a few different files now.
It has thankfully been picked up by our printers.
When I go to check the original Indesign file it's not there at all - there are no hidden shapes on any hidden layers and no trace of the small hexagon shape at all.
I only seem to find it upon opening the IDML file so it must be something to do with saving it out to IDML format?
Is it normal for things to shift or items to move/appear when doing this?