Final Render suddenly darker

[pixelapocalypse]

I have this super weird problem right now. I am working on a scene setup by someone else that was setup as a linear gamma workflow. Now I've been working on changing some of the multimattes, one material setting was changed and 2 render elements were added. EVERYTHING else has remained the same. None of the settings in terms of gamma settings were touched.
Now when I compare this to the earlier version, the final render appears a lot darker. When viewed in the frame buffer and when viewed in Nuke. It's not so dark though that when I put a gamma of 2.2 correction on it in Nuke it's the same again. I've been checking the gamma settings on all the shaders and in the color mapping settings, but it's all exactly the same as the first version.
I have litterally NO idea what's causing this. I'm at a total loss.
What could cause this????

[Morbid Angel]

maybe get us the scene to look at?

I can suggest to check the lights / gi, nothing is turned off by chance?

[yolov]

So it is darker in NUKE and lighter in the VFB? If that's the case and if you're rendering to EXR files, then it might be just the display sRGB correction that the VFB applies (or other display corrections like exposure etc, that are not saved to exrs from the VFB). Could that be it?

[pixelapocalypse]

haven't touched lights or GI, and no nothing is turned off.
Although in the original there was a difference in the VFB and NUKE, that's probably due to sRGB as you suggested. The difference is now the same though. It's both darker in VFB and in NUKE.

[yolov]

Can you share some pictures from before/after? Any chance you can share the scene (from before and after) so we can have a look?