I'm having problems with my Polycom VVX400 phones. It's the first time i've configured them to work with Aircall.io, our SIP provider.
I have them registered just fine and I can make calls, but when I dial it, it rings and works once (I can hear and speak), then if I hang up and dial it again, I can no longer connect to it. I get an audio message saying this number is not registered. If I wait a few minutes, it starts working again.
It sounds like a connectivity issue. Any ideas?
Thank you