Samsung's 2018 flagship smartphones, the Galaxy S9 and S9 Plus, have remained eligible for Android security patch upgrades, even if only 4 times a year. Now, however, that has come to an end, leaving the devices completely cut off from software updates - official ones, that is.
https://www.notebookcheck.net/Samsung-takes-the-Galaxy-S9-series-off-its-supported-devices-list.612250.0.html