mikrotik client - mikrotik ap seamless roaming , maybe loadbalance ?

RouterOS Wireless Networking
5

Very likely unrelated to the issue at hand but there are a couple of possible problems in your Ax2 configuration.

  1. don’t use vlan 1 unless you really know what you are doing
    http://forum.mikrotik.com/t/the-twelve-rules-of-mikrotik-club/182164/1

  2. you have a few places where something has been replaced by an * (asterisk) followed by a (hex) number, these are leftovers, references to things that have been removed or renamed, see point #21 here:
    http://forum.mikrotik.com/t/gp-csa-for-mikrotik-devices/182176/1