Hi,
many times I get the same issue, no “landing line” on the runway and no matter how you land, it’s going to be a fail.
Until they fix that, I was able most of the time to have this “line” back and so the challenge will be valid, with this walkaround:
uninstalling FS2024 and reinstalling, but it’s not practical, so I’ve tried to just go in the library, deactivate the buggy scenery, quit FS2024, restart, reactivate the scenery, quit FS2024 and restart it.
Most of the time it will fix the buggy challenge.
I hope it helps in the mean time.
cheers