A green "URL is available to Google" next to a red "URL is not on Google" is one of the most common sights in URL Inspection. The live test passed but page not indexed, and nothing on the screen says why. The short version: the two results answer different questions at different moments. The questions below cover what each one means and where the real reason is hiding.
Only reachability. Google's help page states that the live test "confirms if Google-InspectionTool can access your page for indexing." It fetches the page in real time, applies robots.txt and noindex rules as they stand right now, and reports whether anything blocked the fetch.
The same page is explicit about the limit: "There is no definitive test that can guarantee whether your page will be included in the Google index." The live test skips several checks that decide indexing: sitemaps and referring pages, duplicates and canonical selection, manual actions, removals, quality issues and temporary blocks. A page can clear every live check and still be left out for a reason the test never examines.
Because the default view shows what Google's index knows from the last crawl, not what the page looks like today. The live test is a snapshot of the present; the indexed verdict is a record of the past. There is a second detail that surprises many people: the live test result is for you, not for the indexing system. The troubleshooting guide says plainly, "Google does not use this information." Running the test changes nothing in the index.
Switch back to the indexed view and expand Page indexing. One of these fields almost always carries the answer:
Not on its own. The request queues a recrawl; Google says it "does not guarantee that the page will appear in the Google Index," and there is a daily limit per property. If nothing on the page or in its signals has changed, a second request produces the same outcome and uses up quota. The sensible order: find the field that explains the gap, fix the cause, run the live test once to confirm, then request indexing one time.
It depends on which field flagged the problem: