keyAgreement bit was set in the configuration file for the SECC leaf certificate (seccCert.cnf in the RISE-V2G-Certificates > configs folder)

RISE-V2G-Certificates/configs/seccCert.cnf

@@ -10,6 +10,6 @@ domainComponent			= CPO
 
 [ext]
 basicConstraints		= critical,CA:false
-keyUsage				= critical,digitalSignature
+keyUsage				= critical,digitalSignature,keyAgreement
 subjectKeyIdentifier	= hash