you can try a reset by unplugging the power from all phones on this system and the phone line for 30 full minutes.
But if that doesn't work, unfortunately that one has an internal electronic problem.
I hope that works for you but I have to say I from all my years of experience I don't like Panasonic for any of their products these days. They used to be great but not anymore :-(
If that works GREAT!
If not you will need to exchange that one for a new one. Since it's so new, you can do that at the store of purchase.
They will simply replace they system for you.
I know this one all too well lol.
In any case, I will stick with you until this is complete.
Please rate my service kindly.
Also it is the only way I am credited for my time and expertise with you.
Once you rate, I will be notified and will add your question to my priority list so you can reach me anytime until this problem is solved.
Then you can reach me by simply replying to this message anytime.
Thank you Gordon and have a great day!