FortiNAC system backup fails when using GUI

I’m running v7.6.6 on FortiNAC. When I issue ‘backup now’ on the system backup using the GUI, it seems to work. However, the file never shows up on FTP server. In fact, no packets are generated at all towards the FTP server, thus ruling out syntax.

When I run the command from the CLI, I see the packets and the file is accepted by the FTP server.

execute backup config ftp / 10.99.3.206:21 <user> <password>

Any ideas why GUI not working?