Hello & Welcome to Just Answer,
Sorry I didn't see your question earlier and to hear of the issue you are having with your phones.
To help you with this issue, may I ask:1) The Make & Model Number of the phone system you are working with? That should be printed on the bottom or back of the main base unit of the system (you may need a magnifying glass to read it).2) WHERE exactly are you seeing this letter P appear?
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, ***** *****--. .-(im)