Secret Alerts quit working

Several entry sensors  work as they should but two have a problem.  One entry sensor appears to be working alarm wise, but it never would sound the alert when the door opened.  The other gave the alert for over a year then all of a sudden quit.  It appears to be functioning properly alarm wise.. Both  tell me when they are open on the keypad. I have installed two new entry sensors, but they still do not sound the alert.    Another oddity as well, when I open my back door, the keypad tells me about it, but the message clears itself as soon as the door is closed.  These two give the message about being open or having been opened but the message has to be cleared manually. As a lesser issue, none of my motion sensors ever provided an alert.  I like having the secret alert as a means to let me know that the sensors are working.