I noticed the same Problem. Yesterday I updated the SimAppPro to Version 1.16.88 and proceeded with Firmware-
Updates for MCDU-Cpt (v1.04), MCDU-Co (v1.04) and btw.ECAM (v1.01). After loading MSFS2024 and iniBuilds A340-300
respectively restart SimAppPro all was working fine, that means : FCU, EFIS 2x, MCDU (2x), ECAM and AGP.