Went from 6.42rc24 to 6.42rc41 and it broke my dual WAN configuration, its similar to this configuration except I am just using 2 WANS with a 3:1 ratio, ie one WAN gets more traffic. https://aacable.wordpress.com/tag/mikrotik-howto-combine-multiple-wan-links/ Cannot roll back either or force a downg...
I am running into this problem also. What other network devices are you using?
The switch is connected to Unifi 16xg using a 10G fiber module(port SFP1) , the unifi switch is then connected RB3011 that is the DHCP server.
I am going to roll back to 2.6 and see if that makes a difference.