Inbound access service

hi, i have 5 peplinks balance 580, and i need to forward a specific port for a host and dont work.
for example, i configured in the inbound access server the host ip, then i added a service
with the wan3 ip public 187.x.x.x to forward traffic on the port 3389 to the host

in the lan i can do remote desktop for this host, but with the ip public dont work.

i did this same in the other offices and dont work. I check in this forum and only see that configuration its ok. could be a problem of the version, or what else i can check.

thanks in advance.