The banding you are seeing is expected with the FP10 format. The format is 6 bits mantissa and 4 bit exponent. So from 0.5 to 1.0 you have 64 unique codes (2^6). 1 / 0.0156 == 64.
The banding is a quantisation when storing to the FP10 blue format.
A solution is is to add noise or dither at export time to mask the banding artifacts.
Here is a great presentation on this.