I actually have the dhcp server on the bridge, which has all ethernet ports included in it (except sfp-plus).
[admin@MikroTik] > /ip dhcp-server print detail
Flags: D - dynamic, X - disabled, I - invalid
0 name="dhcp" interface=bridge lease-time=7h address-pool=default-dhcp bootp-support=dynamic bootp-lease-time=forever authoritative=yes use-radius=no lease-script=""
allow-dual-stack-queue=no
[admin@MikroTik] > /interface bridge export
add bridge=bridge comment=defconf interface=ether2 learn=yes
add bridge=bridge comment=defconf interface=ether3 learn=yes
add bridge=bridge comment=defconf interface=ether4 learn=yes
add bridge=bridge comment=defconf interface=ether5 learn=yes
add bridge=bridge comment=defconf interface=ether6 learn=yes
add bridge=bridge comment=defconf interface=ether7 learn=yes
add bridge=bridge comment=defconf interface=ether8 learn=yes
add bridge=bridge comment=defconf interface=ether9 learn=yes
add bridge=bridge comment=defconf interface=ether10 learn=yes
add bridge=bridge interface=ether1 learn=yes
I've moved my ether1 on top in the bridge port list, I'l check if that makes a difference.
Edit: nope, drag and drop works in winbox, but if I try to drag 'ether1' to the top, it goes for 1 second and returns to the bottom of the port list.