So I am using a special fixation cross that I run as a .png image.
In the builder, when there are multiple images presented simultaneously, the one at the bottom overlays the others - as wanted with the fixation cross.
I noticed that this is not the case in Pavlovia, the fixation cross disappears under the other image.
This is surely a known issue and has been discussed extensively. Would be very grateful for pointing me in the right direction, thanks