It looks to me like there's no glue under the rails. In reality, you've been done a favor and don't realize it because now you can hand lay it without the joints.
If it was me, I'd pull ALL the rails out. The stringers will hold the ties together. Pull out the staples from ONE side of the rail space, leaving the other ones there for alignment. Get a tube of walthers goo, pliobond, or something else of a rubbery contact adhesive. You need to be using Ross track to do this. Gargraves wont do this because of the rail profile.
Lay the crossover where you want it, take the tracks you plan to put adjacent to the crossover, remove the same number of ties as exist in the crossover (pull the spikes cut the stringers where you need to and carefully pull them away from the rails), mark where the rails will meet the diamond in the crossing (could also just do it with a protractor at 22.5 deg), cut them in a straight line with a dremel and hand lay it together without the rail joints. Once it all fits the way you're happy with, apply a thin bit of whatever glue you chose to both the ties and the bottom of the rail, stick it together. That will hold it for good, but usually what I do is squirt a blob of superglue on a card, take the spikes I pulled out, dip the ends in the super glue and stuff the ties back in the holes.
If you just want to fix it.... just do the glue step as above.
