Location Trophy for Pandora glitched?

I seem to have a bug in my game that is preventing me from attaining the last Pandora location for my Platinum Trophy.
I only need the “Cistern of Slaughter” location checked off, but it wont register that I’ve found AND completed this activity twice now.
I’ve switched my game off and on, gone away from the area and fast travelled back again, pretty much tried everything and yet this location remains at 0/1 locations found. How can it be at 0/1 found when I’ve completed the activity twice???
It’s really frustrating as it’s the very last thing needed for Platinum trophy.

Any help appreciated.