Automatically arm smart home monitor

I’m not sure why your Geolocation mobile presence would re-trigger it’s Geolocation presence as ‘member isn’t there’ when it’s already outside the Geolocation zone and hasn’t been inside the Geolocation zone and left it again. I have done the same thing and it leaves it off, but I haven’t done it in a long time. With all the mobile presence issues SmartThings was been experiencing lately, they may have change something. I’ll have to try it again to see what happens nowadays.

I use an Alexa virtual switch with a Smart Lighting routine.

Alexa virtual switch which I simply named it ‘Intrusion’.

Smart Lighting
What do you want to control,
Intrusion

What do you want to do,
Turn On

Select Trigger
Open/Close

Which Open/Close Sensors
I selected multiple multipurpose sensors.

Turn On when,
Opened

More Options
Only when Mode is,
Night

Note: Night Mode is set when going into Armed Stay.

Alexa Routine
When Alexa virtual switch is Opened,
Then Action Messaging/Send Announcement ‘Intrusion’.

And, if your not using the Alexa Momentary virtual switch, then add turn Off the Intrusion Alexa virtual switch.

Update: Alexa virtual switch