I started rendering with Branched Path Tracing after learning about the benefits. However, after waiting for hours for a render to finish, the renders always end up with some blocks looking like they completed and then some MUCH more grainy (like they didn't complete...however the process does complete 100%). See images here. Am I doing something wrong?? This seems like a clear bug.
You can distinctly see the clearer blocks vs the ones that look like they had way less passes. I still don't understand how this makes sense.
Edit: Tiles are 256 X 240. I am using an iMac 2017 with 4.2 GHz Intel Core i7, 40GB RAM and AMD Radeon Pro 580 8GB. I know AMD cards aren't the best for Blender but it works totally fine outside of Branched Path Tracing. I am also using the latest daily build and using CPU + GPU...could that be it? I haven't tried in 2.79b because CPU + GPU is just so much faster for me.