Xiaomi has seeded a new global MIUI 12 update for the Redmi Note 8. V12.0.2.0.QCOMIXM should bring all global handsets onto MIUI 12 while upgrading them to the November 2020 security patch. The update will be a 2.1 GB download for handsets that are currently on MIUI 11.
https://www.notebookcheck.net/The-Xiaomi-Redmi-Note-8-receives-a-fixed-global-MIUI-12-update-that-also-contains-the-November-security-patch.505804.0.html