Hello & Welcome to Just Answer,
Sorry to hear of any trouble.
May I ask:
1) if you can CONFIRM the model of your system? I only ask because MOST Panasonic cordless systems have only FOUR numbers in the model number.
2) The TOTAL number of handsets you have with this system?
3) If more than one handset, do ALL handsets have this symptom?
4) Are there ANY messages displayed on the handsets? If so, what is the exact message?
I see it has been a few days and I just wanted to follow up to see if you have any more questions concerning this issue or if the issue was resolved.
I look forward to any further questions or results that you may have.
Thanks, ***** *****