Hey @Slumsnake I’m having exactly the same problem. Just updated from 5.4 to 5.5 and the shadows are way darker! All lights and the PP are the same. I also checked if something is changed by default in the project or scalability settings but found nothing.
I have a lot of differences in my scene, due to indirect lighting.
UE 5.4
UE 5.5
Did you found any solution?