Zyxel SCR 50 AXE Portforwarding

Hello, i have a port forwarding problem. I recently changed my netgear prosafe firewall for a Zyxel SCR50AXE. I have a cctv system that needs to have some ports open. My old firewal had the ports forwarded and the isp moden is in brtidge mode and i could see my cctv for the wan. But whit my new SCR50AXE i can not get the ports open. I made the rules in the firewall but the port won't open. What did i do wrong? Can Someone help me?