While looking into FINERACT-902, I peeked at the OpenJPA Dev List and coincidentally noticed https://markmail.org/thread/ihfdh2ylx2hd6nrm re. an upcoming OpenJPA 3.1.1 release (we're on 3.1.0) - we should upgrade to that!
Notably OPENJPA-2713 and OPENJPA-2798 are of direct interest.
[JPA-2.2] add support for Java8 Date/Time types
OpenJPA need to be more Java11 friendly
Upgrade Fineract 1.x to Java 11 and Upgrade Dependencies to latest versions
GitHub Pull Request #794