Cinnamon desktop environment is bugged for me, both my a95x r2 (amlogic s905w) and a95x f3 slim (amlogic s905x3) showing no display, blank screen like no input after loging in.
My suggestion for desktop ubuntu based varian, better change it to Mate desktop. The armbian desktop cinnamon varian based on ubuntu is now work for me after switching to mate desktop