Unable to make routing(gateway) between interfaces.

[ums]

Dear whom it may concerns,

I tried to create a gateway in order to make routing between interfaces on Pfsense 2.4.2-RELEASE-p1.

I have 3 networks(192.168.2.0/24, 192.168.12.0/24, 192.168.5.0/24) running.

I was succeed to create a gateway interface desktop -> 192.168.2.18 as attachment before.

Currently, I tried to make a gateway interface desktop(192.168.5.0/24) -> 192.168.2.55(Gateway ip address), but i was not able to create a gateway as attachment error message.

Please kindly advise me ASAP.

Thank you.