cmd+shift+9 don't work

[Drake3182]

Hi everyone.
I recently purchased a mac and installed the latest version of Illustrator on it. After a couple of uses the shortcut to bring the object underneath has stopped working. Being new I don't think the problem depends on the mac. I also had the same problem on my old Windows 10 PC.
Anyone know how to fix it without having to change shortcuts?

Thanks for the attention.

[Ton Frederiks · Accepted solution]

Try Cmd Shift [