Consider the following situation:
A crossing of four directions: north, east, south and west.
On their own, the rail from East can't actually connect to the rail to South since they are too close, and instead they display the endstops:
But when the rail from North to West is overlaid, the endstops disappear, all rails overlap and there appears to be no problem at all.
Even when using the Signal overlay, the rails seem to intersect properly.
They also appear to form a perfectly functional block.
I've tested all possible configurations, and only East to South isn't possible, the others work just fine.
It's a misleading visual bug that took me a while to understand that two of the rails can't actually connect. I first thought this was a signalling issue, but as evident from the first few screenshots without signals it's not a signal issue.
