Hi James,
I think we figured it out.,
If you use a KEK with the "import" parameter to upload a BYOK from an HSM, you need to define an expiration.
But the expiration does not need to be 24 hours, e.g. we defined a date in 10 days which will give us enough time for the operation.
So, unlike AWS KMS, where the expiration seems to be a fixed 24 h, Azure KeyVault lets you define this timespan.
We will do the operation on Sunday, then I know if this worked...
Regards,
Franck