[RAW Photos opening up severely underexposed]

When taking raw photos in camera they appear correctly exposed, histogram if centred, yet when i open them in affinity to edit they look nearly black. 

I have had affinity for 4+ years on a windows laptop and never had any issues. I have just re-downloaded 2 days ago on a new windows laptop and now everything i open looks nearly black by comparison to the in-camera and laptop previews. It is opening in the develop persona due to being RAW. 

What settings need to be changed for this to stop happening? it is also applying lens correction and detail refinement automatically without me asking it to do so - straight after downloading affinity so i havent set it up to do this. (Neither of these things when turned off undo the exposure issue). 

[RAW file from D750 showing dark/washed out/dull in Affinity but fine on camera??]

Recently bought Affinity photo and been using it to edit RAW photos taken on my Nikon D3100. No problems when looking at photos in camera or in affinity. Just upgraded to a Nikon D750 and found that when i open the photos in Affinity they are much much darker and extremely washed out compared to when viewed in camera. Does any one know how to fix this difference that Affinity is showing??