Cannot create virtual subclients

Using UrBackup 2.3.8 installed on Windows.

According to the server admin manual you can add virtual subclient names after which additional clients should show up in the form client1[subclientname].

I have enabled “different settings for this client”, then added 3 virtual client names in the form
sub1|sub2|sub3

That is exactly what the manual says. However, no new client names are showing up anywhere. I also restarted the server just to be sure, nothing happens.

What else do I need to do?