My AI keep getting stuck on a arched bridge, that has this yellow clipping. I removed the bridge, have resized the yellow clipping, rotated it. The nav mesh goes underneath the actual parts? There is nothing else there other than the yellow parts on the screen.
You could place a passthrough modifier, to bridge the gap. It’s possible that it doesn’t compute paths that are vertically aligned
Just inserting a pathfinding modifier into the parts made the nav mesh move up 
not gonna question it and just continue.
Have you tried making the bridge less steep? Here in the first video Character Pathfinding | Documentation - Roblox Creator Hub the NPC also walks over a bridge but that bridge isn’t as steep as yours as it seems.