i have the following setting
public ip:xxx.xxx.79.45
internal ip:192.168.0.1
srcnat from 192.168.0.4 to xxx.xxx.79.46 (my pc)
dstnat from xxx.xxx.79.46 to 192.168.0.4 (my pc)
route:destination 0.0.0.0/0 ,G.W:xxx.xxx.79.41 pref src:xxx.xxx.79.45
when i look at the routing table i see that MR mikrotik changes the Pref src to xxx.xxx.79.46
and i dont want this isssue to happen. 
I think mikrotikls has to solve this problem as soon as possible 