Hi, knowing Affinity reasonably well. That tells me that the file you’re opening isn’t the raw file.
How are you importing the image into Affinity? My approach through all cameras I’ve owned has always been to use card readers and place images in a folder and open using software, in which case I’m making the selection of what image file to open.
I’ve only come across that problem when using an ‘open with’ or ‘edit with’ option in software such as Photos on a Mac where by default it will send a jpeg rather than raw file.
hope that helps, but without knowing how you are importing the image from your camera into Affinity it’s hard to say much more
Cheers
Andy