: Newer firmware versions (e.g., for the RM502Q-AE ) have "optimized IMEI anti-tampering," which may block these AT commands entirely.
If the IMEI is invalid or blacklisted, the network denies the registration request. This security measure is designed to prevent the use of stolen hardware on cellular networks. quectel change imei
Before attempting any modification, be aware of the following: : Newer firmware versions (e