hello s212367,
did you also execute gen_ekb.py to generate an EKS image?
in the developer guide, [Tool for EKB Generation], that sym2.key is equivalent to ekb.key
please see-also Topic 270934, we’ve also check disk encryption with a custom key worked normally.
you may also refer to Topic 271974, to have hexdump to examine the EKS image you’ve created.