Some toolbar options are greyed out, cannot add to menu bar

MacBook Air M2, Safari 18.5 The Search and ± buttons suddenly went missing from my menu bar. So far, I have reinstalled Mac OS Sequoia 15.5 from Recovery, changed the search engine from Google to DuckDuckGo. The above buttons and some others are greyed out individually and in the default toolbar. I can use the Apple menu bar to search (sorta) and History to navigate + & - but it's pretty awkward. TIA.