Post-processing with HDRP turns off on Play

So, I'm having this issue happening all of a sudden, where it seems like my post-processing turn off when I hit Play in the Editor. I've tried building and running, but get the same result. I'm most certainly not messing with any effect in code, just movement so far. Any ideas on why this is happening? Or suggestions? Thanks a lot!
The following is an image that shows what's happening. As you can see, even the skybox gets significantly darkened.