Does anyone know of a way to keep them in the tracks? If we go over a rough road, one or the other is off the tracks when we get to the campground.

Ours has an L bracket in the ceiling between the 2 doors that keep them from moving to far one way or other and fall off their tracks

If it came that way, that explains the L bracket that was on the floor of my closet when I picked the trailer up.

Yup
There you go.
If you look you will see where the screw was

Ours has a wooden block held in the same location with a single screw. I remove the wooden block to get the doors out of the slider.

There should also be a hook and eye bolt latch on the outside bottom of the doors that latches them together when in transit.

On one of my trips this year, when i got there my doors were laying on the ground.. The L bracket broke.. I went to the HD and got 3 or 4 of them and put them ALL up there to make one LARGE angle bracket this way if one breaks,in transit , I have 3 more to hold them in.

I have the hook, but it pulls the bottom of the doors together tight enough that the tops of the doors spread. Could you send a photo of the block?

I have the hook, but it pulls the bottom of the doors together tight enough that the tops of the doors spread. Could you send a photo of the block?

The trailer is in storage. The doors are tightly together top and bottom. I had to remove one slider this summer and adjust the slope because the doors would not come together at the top when the bottom edges were together. The wooden stop is about an inch wide by 2 in high by 3/4 in deep

Your door needs adjusted, phillips screwdriver and wedge the door in position to adjust all 4 rollers. About 1/2 hour jog when your cool.