Entry delay has stopped sounding

I've had my Ring system installed a few months, and I haven't made any changes to it lately. It used to be that when I left the house, I would get an "Exit delay starting" message, and when I re-entered the house I would get "Entry delay starting" and after I entered my code, I would get "Disarmed". Now, I only get the "Exit delay starting" message. When I return and open the door, there is no message, and when I enter my code, I still get the "Disarmed" message. Any ideas? Where to look, how to fix? BTW if I try to arm the system with the door open, I get the "sensors required bypass" message, so it seems the door sensor is working fine.