I am subscribing to this thread since it may be related to an age old issue with MikroTik’s BGP not properly sending withdraw update messages.
http://forum.mikrotik.com/t/inject-route-into-bgp-routing-table-problem/6929/1
http://forum.mikrotik.com/t/routeros-2-9-24-is-out/6777/28
http://forum.mikrotik.com/t/bgp-routing-problem-your-opinion/6459/1
I really hope there’s a solution to this. It has been a whole decade(!) and we still have the same problem described in the thread above.