unable to setup Chapter numbering

LibreOffice version on Xubuntu bionicle.

i can not setup chapter numbering in the “Chapter numbering” dialog window.
I can choose Style and other settings in Level 1, but after changing to Level 2, settings on Level 1 are cleared.
Only the last edited level settings are applied after “OK” button.
Setting up multiple levels is not possible.

what am I doing wrong?