Well the first few rules of the Mikrotik Club are:
http://forum.mikrotik.com/t/configuring-wireless-on-wap-r-from-zero/179986/1
VLAN1 is seemingly used internally, and using it externally may create issues:
http://forum.mikrotik.com/t/management-vlan-issue/175412/1
If you really cannot change those UNIFI VLAN 1 settings there is probably some way to configure differently the Mikrotik, but you will need the assistance of some expert members, I have no idea what could be done.