Hi everyone.
After using FSiPanel several times without problems, the application icon has disappeared from the MSFS toolbar (Steam version).
The problem started after an unexpected CTD from the simulator and restarting it in safe mode at the suggestion of the simulator itself.
I've reinstalled FSiPanel three times and restarted MSFS2024 several times. I've also verified that the "community folder" path is correct and matches the one listed in the UserCfg.opt file for MSFS 2024. I can't think of anything else to do. In the meantime, the 2020 version is working fine.
Thanks for your suggestions.
EDITED: Problem solved:
After CTD, several things were disabled in FS2024, which I had to re-enable. I don't know exactly what it was that prevented me from seeing the icon, but now it works.