In some cases the current implementation of the gaussian blur can manifest banding. We are working on reworking the blur, this just captures that the old behavior was off sometimes too.

old gaussian blur (with step 2.0 in fragment shader)

Notice the slight vertical banding in the yellow circle.

experimental gaussian blur (with step 1.0 in fragment shader)

Notice the differences with what pixels are being sampled at the left and top edges. It seems like the old algorithm is grabbing more of the black pixels.

diff