Realme has recently updated its older 1 and U1 models. The new OTA adds a new feature in which the screen flashes for calls. More importantly, it also confers the latest security patch level on the 2 phones. It is also part of the 2019 3 Pro device's latest software update.
https://www.notebookcheck.net/The-Realme-1-U1-and-3-Pro-get-December-2019-security-patches.447255.0.html