Plat E0710P06
The error of H3C T5000 device was identified as H3C US552S-XE, and the corresponding device snmp test also passed.

Perform MIB testing on the device. The read values are predefined in the device definition, and the corresponding device is H3C US552S-XE.

Acknowledge with the device-side engineer that the device definition in iMC is correct, and the issue lies with the device. Both H3C T5000 and H3C US552S-XE have the same sysoid: 1.3.6.1.4.1.25506.1.3998.
Follow-up resolution plan: The issue is expected to be resolved in the upcoming release of H3C T5000, with the version number tentatively set as 9900P24.
After upgrading H3C T5000, it will have a new SysOID. A device definition for the new SysOID and H3C T5000 needs to be configured in iMC.