How to stop Crop defaulting to custom (1x1)

Hi all, 

My first post on here, I've been using Lightroom and Photoshop for years. 

All of a sudden, when I go to the crop overlay, it seems to auto set to custom aspect which for whatever reason is 1x1. 

I want to keep this as to as shot/original aspect ratio, as its always been before. This is usually 3x2, which I prefer anyway. 

I have tried going into custom and putting 3x2. But on the next image, when I go to the crop menu, its gone back to custom (1x1) as default. 

Does anyone know how I default this back to as shot?

I have never changed any default crops, neither have I cropped to 1x1 previously so not sure why this has started. 

Cheers in advance. 

Sam