H.264 3840x2160 @ 30P L5.1 support

Cannot produce H.264 3840x2160 @ 30P L5.1 format out of After Effects / Media Encoder. The resolution always changes to 2304x1296. I think maximum level for 5.1 should be able to do this (3,840×2,160@31.7), according Wikipedia atleast (https://en.wikipedia.org/wiki/Advanced_Video_Coding).

Level6 can do such format but on end system the format seems not to be very smooth.