NAT Range of Ports

I am new to RouterOS and am trying to setup for the first time.

I have been able to successfully forward/NAT single ports to inside addresses, but having a difficult time with a range of addresses.

For my phone system I need to forward 15000-15511 UDP to 192.168.253.254.

Using Winbox I added a NAT rule

Chain: dstnat
Protocol: 17(udp)
Dst. Port - 15500-15511
In. Interface - ether1-gateway
Action: dst-nat
to Addresses - 192.168.253.254
to ports 15500-15511

However this doesn’t seem to be working.

Is there something different when it is a range of ports that has to be done?