Xiaomi is moving on ahead with its updates to MIUI 12.5, and the latest phone to be graced with this version of the skin is the Mi 9 in Europe. It's actually a double celebration for Mi 9 owners, because not only is the phone getting MIUI 12.5, but the underlying Android version has changed too, jumping from Android 10 to Android 11. It's a big one, then, both figuratively and literally - the download is 2.4GB, so if you're on a capped data plan make sure you use Wi-Fi to grab it. The new build is labeled MIUI V12.5.1.0.RFAEUXM, and as we mentioned already (and that "EU" in the name...
Source: https://www.gsmarena.com/xiaomi_mi_9_is_now_receiving_the_miui_125_update_based_on_android_11-news-50121.php