Hi, I am having the same issue and after changing the setting to 32 bit HDR it still stays the same, ie the image looks very flat and underexposed and appears very very dull on screen.
I have been trying to sort this issue out on the interface and by adjusting the exposure and gamma setting to 1.35 each in the '32 bit prevew' window at the bottom right of the interface I can get the image to look the way it should. My problem now is that I cannot set this setting permanently for all raw images or at least I do not know how to set it permanently for all images. I thought an 'add preset' might work but alas, no.
Can you assist me any further, please ?