I suggest you find Panasonic's phone support for your country and call them.

http://service.us.panasonic.com/OPERMANPDF/KXTG7622-MUL.PDF on page 94 has service contact information.

"Your cellular phones must be Bluetooth
wireless technology compatible with this

If it worked before and Apple updated the phone, it is possible it is no longer compatible. Panasonic may know this.