5224 is not supported as a teleworker !!!
There's actually no such thing as a teleworker handset on the 5000 anyway, it's a either a native phone, on the same flat network as the system. Or a NAT Phone, has to traverse NAT to get to the system.
I bet the OP is glad you don't look after his telephone system!
Hello, I seem to have a problem with my phone, i've moved house and it's stopped working.
Your phone isn't supported as a remote phone
But it worked at my last house and my house before that
Yeah it's not supported
But it used to work
But it's not supported, you need to buy a new phone, might as well upgrade your system as well.