There are many other threads you can read on this forum and the MSFS Official Forums about this, but in short, Asobo introduced a bug into MSFS 2024 with SU4 that completely broke state saving for all aircraft that use the same method as mine do. We have talked about it at length on the developer forum, so hopefully we will have a solution with SU5.
In the meantime, here is a workaround posted elsewhere on this forum, which does seem to be working for the time being: "End your flight, start a new flight, then exit the game once loaded in, and that may cause things to save correctly." Sorry for the inconvenience! Let me know if there is anything else I can do for you while we're waiting for a solution.