Version: 18.104.22.168 / LibreOffice Community
Build ID: 47f78053abe362b9384784d31a6e56f8511eb1c1
CPU threads: 4; OS: Linux 5.4; UI render: default; VCL: gtk3
Locale: en-GB (en_GB.UTF-8); UI: en-GB
This issue may be specific to Linux (if I recall correctly, Windows 10 works OK). It is no longer possible to reduce the width of the Navigator or Sidebar. As a result they are very wide, space is wasted and the effective viewing area of the document window reduced.
I believe that this is a regression since, using Linux Peppermint OS on an old PC, I was able to resize the sidebar in an old version (pre 6.3) of LibreOffice. However I don't know exactly when the regression occurred after that.
Thanks for reporting.
I don't know exactly which version changed the minimal width of sidebars (to be more consistent across all modules, IIRC), but turning minimal width off seems to be a frequently requested option by users, and it has already been implemented as an expert configuration for version 7.1.5 and 7.2.0 (and of course higher).
Marking this as a DUPLICATE.
*** This bug has been marked as a duplicate of bug 140360 ***