Try assigning the IP to ether1 and the dhcp server to the bridge.
I use the CLI and the dhcp server setup.
/ip dhcp-server setup
If I have to enter ANYTHING but the interface, then ‘enter enter enter’, that interface or dns is not set correctly.
I assign an IP to only one interface on the bridge. If you assign static IPs to other interfaces on the bridge, insure that when you setup the dhcp server, don’t just ‘enter enter enter’. You need to set the address range above or below all your static IPs.