I can only repeat and confirm I can't reproduce it anymore. It happened 100% of the times before the update, now it never happens, and I tried all kind of combination of calling Stairs, and with different airplanes too.
However, the fix that has been posted already is only temporary, and it's likely not fixing every situation, because I suspect it's related to timing and system overload and, since I CAN replicate it if I remove the fix for testing, at least this can debugged and investigated.
And, as already explained in other posts, since it doesn't seem like an obvious mistake that can be fixed like all the other fixes that has already been posted minutes or hours at most after they have been first reported, I need to wait to discuss it with the other GSX programmer (who is the *main* GSX programmer), starting tomorrow.
So, no need to continue posting about it. Even if I cannot replicate it anymore after the latest fix, I KNOW what I can do to replicate it, so the issue it's confirmed, it will be worked on, and we'll obviously release a fix as soon as possible.