It has been confirmed there are a few problems with FS2024 current official through the latest beta.
- There is a known bug regarding the simconnect FlightPlanActivate functionality where it does not trigger a subscribed event or triggers at unexpected times, and when it does trigger, it, it does not contain the flight plan file name, thus we are unable to load it
- At startup of FS2024 there is a FlightPlanActivate trigger on an unused mission flight plan file (which does not exists, is corrupt, and or is in the wrong format)
- The design change in FS2024 using the EFB to load the flight plan does not automatically create and load .pln files, instead sending data through various other new functions and API (JS and/or WASM) which are not available to simconnect apps like the ASFS client.
Thus, there is no way to make this work reliably, at this time, even if manually loading a .pln in FS2024. Thus ASFS auto flight plan load is not currently supported in FS2024. We'll re-visit this on an ongoing basis. The state of the previous (and as documented, should be working) simconnect functionality is unknown at this time. With the known bugs/issues, we hope that the eventual fix of these will allow things to work or at least allow us to alter things to work appropriately.
In the mean time, we recommend that you use manual save/load features in the EFB flight planner and ASFS, or use SimBrief which supports autoloading outside of these FS2024 features/bugs.