Thank you for that information. unfortunately this is a sign of an electronic failure in the phone system. But sometimes a reset by removing power from the phone will clear this. It works about 50% of the time, so please try that first.
To do this, unplug any phone lies from the phone in question, then also remove power from the unit by unplugging it fro the wall.
If it works great!
But if not you would need to have this serviced by a local phone repair technician.
I wish I had better news for you on this I really do, but please let me know how it goes with the reset?
I can also help you find a great tech to fix this for you if you need one.
In any case, I will stick with you until this is complete,
Please rate kindly thus far, it won't cost you anything to rate my service to you kindly,
Then you can reach me by simply replying to this message anytime.
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Thank you and have a nice day!