Not sure if it’s exactly the same issue as the one you reported, but offline BGL traffic is completely broken since SU10 …
i think you get some explanations here → Offline AI Traffic - Windows system time used to spawn AI Traffic - no effect changing sim time/date
So if you do some schedules yourself you just won’t find your aircraft at the desired time/location, it’s all spawned via broken/buggy rules 
hasn’t been fixed since SU10, it’s fair to assume that it will never be fixed unfortunately because i don’t think they care about that, most people use live traffic or external traffic generators programs and AI traffic certainly hasn’t been the strong point of MSFS, it’s even a lot worse than it was in the 20 years old FSX (most of the rest is fantastic though ).