Hi, spent a while trying to work this out but not getting very far.
Is it possible to remap the ports so that port1 is the master switch port, 2+3 are slaves, and 4+5 are router ports?
Reason is I’d like to power the device via POE and my lan switch will do that, so will plug into port 1.
4 + 5 would be uplink ports to my ISP, (MLPPP running over each).
If so, can you give pointers, ta.
http://wiki.mikrotik.com/wiki/Manual:Switch_Chip_Features
http://wiki.mikrotik.com/wiki/Manual:Interface/Ethernet
/int eth set ether2,ether3 master-port=ether1
/int eth set ether4,ether5 master-port=none
Then you can set addresses on ether4 and ether5.
I tried that but it failed to apply as a master port already exists.
Remove the master port setting from all interfaces, then choose what one you want to set.
I can’t do that for eth2 as it is already a member of the bridge.. Can’t seem to change that value though?
Not getting a DHCP lease on eth1 even though I’ve set all ports to be switch ports. What gives.
Figured it out - found how to change the bridge members. 
How did you manage to remove eth2-master-local from bridge?
(I try to make eth5 the master port)
/interface ethernet> set ether2-slave-local master-port=ether5-master-local
already in bridge
/interface ethernet> /interface bridge
/interface bridge> print detail
Flags: X - disabled, R - running
/interface bridge> port
[admin@MikroTik] /interface bridge port> print detail
Flags: X - disabled, I - inactive, D - dynamic
/interface bridge port>
Hmm, did you try rebooting and/or upgrading RouterOS?
RouterOS is current: v5.25
However a reboot made it work.
Thanks so much for your help!