Currently the category labels in Styles Inspector ("Paragraph Styles", "Character Styles", etc.) are not localized. They are hard-coded in sw::sidebar::UpdateTree in sw/source/uibase/sidebar/WriterInspectorTextPanel.cxx. They need to use the normal SwResId mechanism, as property names do.
Aron Budea committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/core/commit/514a4f302f9f49db5a0b22cbe49bd98191296735 tdf#136868, tdf#136912, Styles Inspector: Translatable categories It will be available in 7.1.0. The patch should be included in the daily builds available at https://dev-builds.libreoffice.org/daily/ in the next 24-48 hours. More information about daily builds can be found at: https://wiki.documentfoundation.org/Testing_Daily_Builds Affected users are encouraged to test the fix and report feedback.