This is a new requirement defined by JPA 2.2.

Again this work is done on 6.0, just need to back-port it although it may be simpler to just copy-port the ManagedBean/ManagedBeanRepository stuff and do the calls by hand since so much is different in that area in 6

Also, consider carefully the following snippet from JPA 2.2, 3.8 Type Conversion of Basic Attributes:

The persistence provider is only required to support CDI injection into attribute converters in Java EE
container environments. If CDI is not enabled, the persistence provider must not invoke attribute
converters that depend upon CDI injection

I read this to mean that it should not be an error (ignore silently) if the application defines AttributeConverters relying on CDI injection, but CDI is not available. But how can we know that an AttributeConverter "depend(s) upon CDI injection"?