@malada 

Some routers allow the address reservation feature to be functional only if the reserved IP addresses are within the DHCP Server pool range. Can you confirm this to exclude this hypothesis. How about other devices in your LAN ? Do they have the same issue or this concerns only these two cameras ? Some cameras have two different MAC addresses - one for the ethernet connection and another one for the wireless connection. Are you sure you're using the correct MAC address when creating the address reservation ?

  @malada 

Well, either expand your DHCP pool to 192.168.1.1 - 192.168.1.253, reboot the router, then test or if you don't want to expand the DHCP pool, use a static IP addresses for these cameras outside the DHCP pool. I presume your router's LAN IP address is 192.168.1.254 ?

There's a third option - if you want to preserve the DHCP pool as it is, just use an IP addtress in its range for the camers, reboot, then test if it works.