Why won't my truck beep anymore?

I drive a ford 2008 escape that I keep in good condition. Usually when I hit the lock button on my keys twice the light flash and I ll hear a beep. It did it earlier. But just now when I went to lock my doors the lights flshed but no beep? I don't know why or what I did. I thought maybe on of my doors was open, so I unlocked and went and made sure every door was locked. Yep all locked and still didn't beep. Very confused on why can someone help!

Try resetting the key FOB so it beeps and flashes when you lock the doors. It may have lost it's programming.