In the router, the radius ports are 1812 and 1813.
/radius print detail
To change the ports
set X authentication-port=1812 accounting-port=1813
Use the new ports, of course.
ADD: If that is a typo, which it probably is, then you should check "/ip firewall nat" for any masquerade rules that might affect either interface. That would be one without "out-interface=ether1" or some other interface.