I'm using Ubuntu 24.02 ARM on a MacBookAir M1 and the appimage will not launch.
I am seeing nothing in the logs and I have made sure the current Joplin app is not running by using Quit in the tray icon.
Is Linux ARM64 support in the pre-release appimage builds?
ARM64 support isn't in any of the official desktop builds, stable or pre-release. This might change with GitHub making ARM64 build servers freely available in the future: but for it's entire lifetime any ARM64 on Linux has always been unofficial.
You'd expect to see exec format error when running via the terminal suggesting the CPU doesn't understand the code it's looking at.
The unofficial Flatpak and Snap distributions do cover ARM64 Linux however.