Alarm or What???

My 1999 Sub sat in my garage at work since Jan/Feb 2019 when I used it for plowing snow a few times last winter. I keep it on a trickle charger so the batts are good.
Started fine & ran good for a 100 mile trip in mid June then I Had it parked at my house on 6-21-19 in South Jersey when the Explosion at the Phila Oil Refinery @ 4:30 AM set off the shock sensor in my Sub! That explosion shook my house so hard it woke me up! Then the Alarm & horn in the Sub started blaring and my 2 way Remote Key Fab started chirping and vibrating like crazy. The alarm wouldn't turn off at first from my room so I ran outside in my Pjs armed it then disarmed it, then that turned off the alarm noise.
The next morning I tried to start it to go to work but it would not turn over. I could hear a click but no starter and not solenoid click either, After I tried starting it again It started right away then drove to work left work drove to my mom's house then it died and now will not start!
I called the alarm co that installed this alarm in 2011. They said once tripped by the shock sensor the alarm is reset by turning on then off then on the ignition to reset the starter cut out. They insisted that as long as the alarm is locking and unlocking the doors the starter cut in not the problem. So if that is true could it be the ignition switch went bad? As I recall reading they are known to fail, is this a symptom of a bad ignition switch?
Is there any other circuit that can cut out the starter just like that ?
Or do you think it is the Alarm system, It is a Compustar I had the installer rig it to the glow plug so during remote start it would only start after the glow plug light went out not on a timer like they wanted to do...
Only other thing i can think to add is that I never had the Alarm starter cut out engage before so wonder if it is a bad relay or something in the alarm system...
So I don't know if I should have it towed to the alarm shop of to a repair shop, any thoughts on this as I don't have time to work on it and would like to take it to Maine for vacation this summer.
Any ideas or thoughts are welcome.

My first thought would be poor battery connection or ignition switch. Since you have an aftermarket alarm system installed, that depends on if you believe them or not (I am not familiar with that system). If you're satisfied with their answer, then I suggest proceeding with the connection or switch route.