Problem with BT8600 answering machine. After a caller leaving a message hangs up, it continues to record a tone (intermittent at first and then continous) for about 45 sec. Is it a setting? Is it a faulty unit?
There may be an issue with your handset. Can you get in touch with the product helpdesk?
Their contact details are on the following page:
BT8600 Advanced Call Blocker