Firewall Networks won't accept a /24 address

So I just did a new installation of FreePBX ver14, and I’m trying to add a few networks into the firewall (which I’ve never had an issue with before) when I try to add my IP address with a /24 sub the box just flashes red and won’t let me add.

I found a Closed bug report on this issue that reports it was fixed with however that’s the version I’m running, I’ve uninstalled and reinstalled the package, and still not working right

Any thoughts? TIA

It was a JavaScript bug. Clear your cache, or just try a different browser until your normal browser expires it.

Thank you! I can now actually say Microsoft Edge has worked for something haha