OnePlus introduced a range of new always-on display (AOD) options with OxygenOS 11 (this OEM's take on Android 11) on its late-2020 flagship, the 8T. Now, one of these, Canvas, is available to this phone's immediate forebears the 8 and 8 Pro in a new "stable" update. The company has also addressed a serious error with a previous software version.
https://www.notebookcheck.net/The-latest-official-version-of-Android-11-for-the-OnePlus-8-series-unlocks-Canvas-on-the-phones.503413.0.html