Yes. OnePlus devices running OxygenOS 13+ (colorOS codebase) now show this error if you use Oppo fastboot commands on a locked T-Mobile or Verizon model.
: If a device has been previously flashed with an incorrect ROM or from an unauthorized source, the internal serial verification fails during the boot process. Hardware Failures The Frustrating Night of Unlocking A: Yes
typically appears when there is a security mismatch between the device's unique serial number and the verification requirements of the bootloader Official Method: If Oppo provides an official method
It occurs when the device's bootloader blocks access to the standard Fastboot interface because the system's security signature or "serial" check fails Why This Happens Security Locking follow that. The process usually involves:
70% (Works on Oppo A series, fails on Find series).