I had a wireless security system installed by Safetouch (who monitors my system) in place of my existing standard security. A suggested upgrade by their technician. The very next day I get in my car to go to work. I pushed the garage door opener on my rear view mirror and opened the garage door (programmed into my car). I then shut it from the outside using the same rear view mirror button. When I got home the door would not open. I came through front door, opened garage door by wall button and pulled my car in. I then was able to shut the door using the button on my rear view mirror. Bottom line is the rear view mirror button works to open door from inside and shut from outside, but will not open from outside. Could this be a frequency problem caused by the new wireless alarm? I have a Chamberlain garage door opener and DSC home security.
Most likely the signal strength is not punching through your closed garage door, possibly because your new security system is causing some interference. That's not an uncommon issue. Here is a link to a video on how to increase the signal reception capability on your opener, it's not difficult at all.