Incomming call from Telia (Anonumous) will not work.

Problem is the incoming from header, Panasonic don't like this from header and the call will never be set up.

Workaround, you have to use IX78 header manipulation to change the incoming from header, to be able to use header manipulation you need at least a SIP Trunk license and a SIP Trunk installation. Add this string after the phonenumber (Forward to PBX account)

?From=$(from.dname)%20%3csip%3aanonymous%40$(from.host)%3e

EX:

08123456789?From=$(from.dname)%20%3csip%3aanonymous%40$(from.host)%3e

This will only work in latest firmware to IX78 5.33F4 or later beta release.