I think may understand what happened…
In your 1st image, out of the 3 available “All curvy routes” had selected to navigate probably on some other than the first “Fast and curvy route”?
Then could be a timing issue, where after rerouting the instruction came immediately from the first of the 3 new routes and soon after the curvy or extra curvy was properly activated with the correct instruction.
Does that make sense?
If that is the case, I can improve the workflow.