Certificate Request + LetsEncrypt = No supported curves

[aarcane]

So I'm trying to register LetsEncrypt certificates all across my network, and I've got this mostly working, except when I try to register a certificate for TrueNAS, I can fill out the Certificate Signing Request, and I can complete the AWS DNS Authentication, however, at the end of all that, no matter which EC curve I choose for the EC Curve, LE tells me "Error parsing certificate request: x509: unsupported elliptic curve". Again, this happens with literally *any* curve I choose in the CSR dropdown. I spent an hour manually re-entering all my constraints and trying all six of them. I'm on Truenas 12.0-U8. Based on the changelog, I see nothing to indicate that this is fixed in 12.0-U8.1 or 13.*, however, I am in the process of updating to 12.0-U8.1, just in case it's a secret, undisclosed fix.