This was way easier than it looked like. On a EL 8 Host /tmp is mounted noexec by default. Editing /etc/systemd/system/tmp.mount.d/tmp_options.conf and removing the noexec mount option made it work.
Figured out by temporarily setting Administer / Settings / Remote Execution / Cleanup working directories to No.
Concerning the dangling symlink I am going to open an issue.