I just came across this text when refreshing PBN knowledge:
- The manual entry of coordinates into the navigation system by the pilots for operations within the terminal area is not permitted.
- Direct to clearance may be accepted to the intermediate fix (IF), provided the resulting track change at the IF does not exceed 45 degrees.
- Direct to clearance to the Final Approach Fix / Point (FAF / FAP) is NOT acceptable.
Still I’ve also noticed the same problem en-route a couple of times where the waypoints weren’t sequencing correctly after a direct-to. So it might very well be a bug.