rich453
Thanks for the tip, as it sounds the plastic is not cracked however with age it deteriorates and bends outwards, rear passenger side is perfect it actually is bent inwards therefore keeps going back into it's place.
I have managed to undo the torx screw holding the corner of the bumper in place and tried to bend the plastic back in gently and it had definitely worked as it doesn't stick out too much now. I'm either going to glue it now or use a hair drier to heat up the bumper a little then hold the corner and hopefully when it cools down it will stay in it's place.
There is nothing that pops out there it's just deterioration process of the plastic.