The tab page starmath/uiconfig/smath/ui/smathsettings.ui contains several icons (all equal to "res/lock.png") that are not displayed in the dialog (gen, kf5,kf6, GTk, Win). + Are these icons needed and displayed somewhere? + What these "lock" icons means? If they are not needed or means nothing, better remove them from the UI file above. May suggest a dialog refactor, at will. This is an easy hack.
This UI is Tools > Options > Math but available only if smath is started directly. Running it as OLE object inside Writer does not show it. The lock icon leads all options, not only in Math. It is shown if the entry is readonly but I don't know how to make the option r/o. => NAB
Olivier Hallot committed a patch related to this issue. It has been pushed to "master": https://git.libreoffice.org/help/commit/20353e3880d977cebd022159ea8ef646f4537bb6 tdf#168146 Restore important detail on MATCH()