Using revealOrder="backwards" in SuspenseList only works for very short wait times

I realize that this is still experimental, but I figured it would still be good to report bugs. If not, feel free to close this issue.

I was playing around with the examples in https://reactjs.org/docs/concurrent-mode-patterns.html#suspenselist and noticed that revealOrder="backwards" didn't seem to work. The trivia items never appear before the posts. After fiddling around with the example in https://codesandbox.io/s/black-wind-byilt i noticed that it works if the timeout is set around 500 ms or below for the trivia items. But if you set it to for example 1000 ms, it will instead wait until both trivia and posts are available.

revealOrder="forwards" seems to work regardless of how long the timeout is.

I tried changing React version to the latest experimental version (0.0.0-experimental-c76e4dbbc-20210722), but it did not seem to make a difference.

Reproduziere das SuspenseList-Beispiel aus der React-Dokumentation und der verlinkten CodeSandbox und vergleiche revealOrder="backwards" mit Trivia-Verzögerungen von 500 ms und 1000 ms. Überprüfe zunächst die gemeldete experimentelle React-Version und das Timeout-Verhalten des Beispiels; abgeschlossen ist die Untersuchung, wenn die Ursache identifiziert und das Verhalten der backwards-Reihenfolge bei längeren Wartezeiten korrigiert oder eindeutig behandelt wurde.