Cannot start the truck with key in the ignition

Just so I am clear, the alarm sounds only for 10 seconds and will stop prior if you just close the door? Also, you are able to start the vehicle by pressing the lock button on the FOB while standing outside the vehicle?

Can you get pictures of the keys and attach them? Also, did you just buy this vehicle or has this issue just started? Are there aftermarket components like an alarm or remote start?

Yes, the alarm will stop when doors are closed and I can start it with the key fob. I have had this truck for 6 months and it just started to have problems.

Okay. Look under the dash and see if you can find an aftermarket box of some sort. There has to be some outside interference with this because it is absolutely impossible for the lock button on the key fob to start the truck. So I suspect someone added an aftermarket system and programmed it to the same frequency of the lock command. It probably operated just fine before but now the system has an issue causing these other issues. It is the only thing I can think of to cause something like this.