Problem sampling uniformly envmap with GGX
How are you randomizing the samples you take? It looks to me like maybe the random values are the same across all pixels in the image, which would explain why you see 10 coherent bright spots when you have 10 samples.
The samples should be re-randomized for each pixel. This should produce a noisy result, with a single blurred-out bright spot instead of 10 (or however many) coherent bright spots.