You surely have 1 brake that is not working. Stop and think about it, if there is more braking on the left side of the trailer it will pull the front of your truck to the right. Take it out for a ride and apply the brakes on the trailer a little bit..not enough to pull your truck around alot because you need to be somewhat safe .. another words be careful..after several miles get out and see if you can feel heat on the brake drums of the trailer..I bet you have one that is cold..it will have a bad magnet or a wiring issue. Report back and let us all know!!
