https://wpt.fyi/results/navigation-api?label=master&label=experimental&aligned shows lots of failures in Chromium. The results are inconsistent between Chrome and Edge.

Those failures do not appear in Chromium CI. They do not appear in the stability checker when CLs are exported. They do not appear when running the tests using wpt.live.

One guess as to why this is happening is due to the unique nature of these tests as testing navigation and history traversal, which makes them sensitive to things like browsing context reuse. Perhaps when collecting results for wpt.fyi, the tests are run in a window that is then navigated to a second test, instead of being run in a fresh window? That would definitely break most of these tests.