Hi Dang Luu,

I think you can check the TPM specification in the section NV Index Deletion 37.2.3 (https://trustedcomputinggroup.org/wp-content/uploads/TCG_TPM2_r1p59_Part1_Architecture_pub.pdf). Maybe, you can use the function TPM2_NV_UndefineSpace instead of TPM2_NV_UndefineSpaceSpecial().

Could you please share with us how you define the NV index? Because, depending on the parameters used, this can impact the way of undefining.

Best Regards,
Renan Moraes