Can't register remote extensions

Hello,

I’ve set up quite a few FreePBX instances, but I’m really stuck with this one. It’s running PBX Firmware: 10.13.66-6, all phones register perfectly internally and can make/receive calls with no problems. Whatever I try I cannot get external phones to register, I’m using CHAN_SIP on port 5060 and have definitely opened the port to the phone server. I’ve tried disabling the freepbx firewall in case that was causing issues but it’s still not registering at all. When I run a packet capture on the router I get 589 Status: 401 Unauthorized. Does anyone know why this would happen?

Thanks,
Jethro

Password mismatch?
Allow/Deny settings?

What does your /var/log/asterisk/full log say about these extensions?

Check Password for correctness