Panasonic KX-TDA0484 Programming Manual page 60

3.3 Data Management
5.
Switch the firmware status of the updated page from "NEW" to "Main Operation Mode".
After the previous step (with or without a reboot), the firmware status of the updated page is still
"NEW". To set the updated page as the active page on startup, you must change its firmware
status to "Main Operation Mode". For instructions, refer to "3.3.2 Handling of Firmware Page".
The following is a sample image of the screen in which you can set the active page on startup:
60 Programming Guide