I have had this problem on another CCR, I can only connect via IP address, it will not connect via MAC.
[admin@MikroTik] > /tool mac-server mac-winbox print
Flags: X - disabled, * - default
INTERFACE
0 * all
[admin@MikroTik] > /tool mac-server print
Flags: X - disabled, * - default
INTERFACE
0 * all
As you can see it is enabled. This is not working while directly plugged into the CCR to any port both from a windows 7 and windows 8 laptops. configuration is default.