I have a project that Blasters (wifi or ethernet) are not showing up as available devices. I see them on a network scan and can log into them to see the IR set up is correct. Manual entry with the IP address and using port 4998 (IR) is not working either. I do not see any router settings (Fios) that would be causing this.
Are you using a hub? I had an issue with FIOS when I switched from Cable Modem. After the FIOS install I could not see any of my blasters and had all kinds of other strange issues. Once I installed an iPhone as a hub, everything worked great. No idea what caused it and spent a lot of time on the phone with FIOS 2nd level support. The person I was working with agreed that something in the FIOS configuration was causing the issue. If I recall correctly, disconnecting the fiber from the FIOS modem also made the problem go away, but then no Simple Control. Hope this information might help you.
Try a Fixed-IP or at least Reserve it’s IP inside the Router-config.
@Chowim reply makes it sound like FIOS Residential-Gateway is somehow selectively limiting network traffic, even on the “safe side” of the Router’s firewall. That is sometimes a disadvantage of these all-in-one residential gateways.