Probably not a good way to fix it, however have you tried to merge your route to a new created route. What I suggest is try to make a new route and merge your current route to that and see if anything happens. A person I helped some time ago had a problem where all his tracks were not showing, switches and everything, also a corruption problem, and this helped in the end.This is a data corruption issue. I found an earlier backup made before this issue occurred and restored it. The problem doesn't exist in this area, or causes the rest of the route to suffer from the problem.
Since I have backups of everything, I'm going to perform some surgery and extract the working part and insert it into the broken route and see what happens after removing the faulty section of course. I'd hate to go back to the older route because I've made some route changes that took me a very long time to implement.