Someone needs to upgrade some searching skills … 
1- http://forum.mikrotik.com/t/microtik-wireguard-to-raspberry-pi/152177/1
2- http://forum.mikrotik.com/t/wireguard-use-hostname-in-endpoint/143014/1
3- http://forum.mikrotik.com/t/v7-1rc3-development-is-released/151711/1 (post 135)
4- http://forum.mikrotik.com/t/v7-1rc4-development-is-released/152002/42 (post 13 indicating it was solved but the issue slipped back in)
I’ll stop here …