Asus RT-AC51U Not Booting Correctly

I have installed LEDE using the ASUS Recovery mode, the firmware uploads and flashes fine, the router then reboots to the point where I am then left with only the power LED illuminated and no way to access the router, the only thing I can do is flash back to stock at this point.

Whats going wrong? I'm using https://downloads.lede-project.org/snapshots/targets/ramips/mt7620/openwrt-ramips-mt7620-rt-ac51u-squashfs-sysupgrade.bin