Thanks Pam, I wasn't sure due to type of problem, but since it was in SN and I haven't had the problem show up in RV (which I have played a couple of times since I bought SN), I thought it might just be a SN problem.
Alll of my doors, and I have several -- main front, dinning room door to patio, another door to sims private patio (what can I say, I built the house I wish I had) and in this one, a door from the kitchen outside to the trash can. One on the garage, that is outside the building.
All are locked to only household, due to zombies trying to get into the door once.
I had an alarm outide the front door and inside the kitchen door. Any one of them opening should have been set off am alarm. He came through the patio door in the dinning room. I watched him open the door, which in other games it would have gone off, and no alarm.
I've built homes with alarms both in and outside and both have worked on thieves; in one home two sims are cops. Three times robbed for this family, once at the old location, and now twice to where I moved the house to a bigger lot.
I have now put alarms on all doors, a couple inside, the patio door in sims bedroom and the kitchen door. The others are outside the door.
I have four games in SN in different types; I know that one has been robbed and the police has been a fairy. I had remodeled the house and didn't realize I had forgotten to put back in an alarm. So that is understandable; but as the thief passed the cop (fairy) coming in he (cop) waved at him. Others I have started but not played long enough yet.
Frustrating ! I didn't know if it was a glitch in my game or something others are dealing with.