That means the path solution is still being generated and Fly To is waiting for the path to arrive, so I’m surprised that you’re seeing the path being generated at all in the first place.
Best bet then is to directly debug DoNNavigationManager.cpp’s TickScheduledPathfindingTasks function. At this point only that can tell us whether your path was truly generated or if there is some other setup quirk that is preventing the data from being relayed…