Since the July 1, 2020 security patch, some notices that appear in ovals at the bottom of the screen that used to disappear after a few seconds like they used to. For example, if I uninstall an app an oval notice appears at the bottom of the screen saying that the app was uninstalled. That notice used to disappear after a few seconds, but since the update it doesn't disappear after several minutes and the only way I've found to clear it is to restart the device (Galaxy S9+). Likewise if I copy text a notice that says Copied appears and won't go away. There are other notices (can't think of which) that do clear properly.
S9+ Unlocked from AT&T, on Google FI (T-Mobile). Android 10.
There is an option in Accessibility advanced settings titled Time To Take Action. We can set a custom time for the notices to remain on screen. Mine is set to default. Some of them timeout before I can read them and others stay visible for around 15 seconds. The maximum we can set manually is 2 minutes.
There is an option in general maintenance for resetting the accessibility settings to their default. Wipe the system cache partition is recommended when issues start after a system update.
Galaxy S9 SM-G960U
Android 10 One UI 2.1
Security Patch Level
July 1st, 2020