2008 scion xb, aps-998

Alright I got a weird question. I have a 2008 Scion xB. Did a APS-998 in it. Did not use the remote start part of it. It is a stick and didnt want to risk it some how. Everything has worked great until the other day. I was on a trip to NM and got in the car after getting gas and was sitting there talking to one of my buddies with the car running. Went to take off and the alarm starts arming itself. Head down the freeway and keeps doing it. I pulled off and pulled the fuse for the alarm. Was in a big group of vehicles so I didnt have time to trouble shoot alot. So I got to where I needed to be, put the fuses back in. checked all the connections. Had a loose one on my hatch wire. Fixed that. All seemed fixed.

3 days later. stop to pick up a buddy. Sat in the car with it running. Go to take off and same thing. Starts arming itself again. Pull over check it again. works fine now. Get home, pull the alarm down. Can not find a single thing loose or wrong. Put it all back in there all is good.

Pick up my buddy again this morning. Same thing now. I drove down the road, with the door kinda cracked to keep the dome light on. Does not arm at all. Soon as you close the door it starts to arm. So about half way to work I check the door and it works fine again. It seems to be only when the vehicle sits running for a few minutes and then go to drive. Anyone got any suggestions?  I have been doing this for a long time and never seen this. I have checked all the doors, checked ignition wires. I dont get it.