Banding on IOS export

Can anyone help me. I have been working on an ArchViz project and my scene looks awesome on desktop, both on PC and Mac. On android it looks acceptable but on IOS I get this terrible banding on all my walls.

It is most obvious around all my light sources. The bake is set to production and this banding is not seen on any other platform. I have only just purchased my apple dev account so im sure this is just a setting i have missed.

Can anyone point me in the right direction to fix this?