Can't Disable Simon XT remotely. Is it unplugged?

I’m not on site.
Electrical Contractor servicing the location I rent was told to use a disarm code. That info probably did not reach ground level worker.
(It’s my landlord’s contractor and I’m not in communication with worker)
Alarm triggered.
Now I cannot disarm.
Last “History” is “alarm”.
When I try to disarm it, it goes back to “Armed” after trying for 30 seconds or so.
I assume he unplugged it, and also disconnected battery.
Is there any other possibility? Radio is fine, new 4G module working flawlessly.
I won’t be at that property for some time and want it to be armed again.
Is there some way to be notified when panel comes online again?

It looks like the disarm command did eventually go through, but it does look like they are disabling it via unplugging it. It looks like they powered it back on, but then unplugged AC again after your commands when through.

The system currently shows a status of disarmed, with a current power failure.

It is not immediately responding to commands I am sending to check signal.