Hi and welcome to JustAnswer,
Thank you for the question and your patience. Should you still need assistance for information purposes only...Initially and on "...rings too briefly..."; how many rings before the answering system takes the call? Or is the Voice Mail system of the phone service provider used?
Hi again Michael,
Please click HERE on how to change then number of rings on a Panasonic KX-TG2721 before it automatically answer the call.