OnePlus has announced the end of its suspension for the build of OxygenOS for the 9 and 9 Pro based on Android 12. The OEM claims that the more prominent of the issues uncovered with the initial version have been removed in this one. Then again, some bugs reportedly still remain.
https://www.notebookcheck.net/OnePlus-starts-its-roll-out-of-Android-12-for-the-flagship-9-series-again.587138.0.html