The new update for Realme X50 and X50m can be identified by firmware versions  RMX2051_11_C.11  and RMX2041_11_C.11. In addition to a new security patch, the latest build fixes the NFC issue after opening Xiamen bus card and optimizes system stability.  Device:

Realme X50 Realme X50m

Software version:

RMX2051_11_C.11 (for X50) RMX2051_11_C.11 (for X50m)

Changelog:

Security Update Android security patch: May 2021 System Optimize system stability Realme bus card Fixed the problem that NFC can’t be used after opening Xiamen bus card

[via]

May 2021 security update reaches Realme X50 and X50m - 52