This one has me scratching my head.....

I bought my truck with a Mini Maxx already installed by the previous owner. It's an 09 QC auto that's been deleted.

For three months the Mini Maxx would turn off when I turned off the ignition for the truck.

Yesterday it stayed on. Now it just stays on unless I switch it off on the plug at the OBD port.
I haven't changed anything or messed with anything in over a month.

Any idea how/why this could have changed. It's a pain in the butt. How can I fix it? Any of you guys had a similar issue?