Judges intervention/Merciful intervention.
The teleport only works if you have a target, and if you have a clear path to that target, in my experience.
If you have nothing targeted it will do the flame blast in place, and if there’s an obstruction between you and your target, it will stop at the obstruction and do the flame blast there.
Jump first, and teleport out of midair. This will give you a clearer line of sight to your target (avoiding rocks and other snags along your path). I’ve found it solves 90% of the failed teleports that I used to have. Can’t speak for Merciful though, I only use Judges.