See WFLY-9064 and JBEAP-10612 for details about WildFly integration test failures (linked).
N.B. I updated integration tests to use WildFly 13 now. Still not 14, but HTH
btw, in the Steps to reproduce field of https://issues.jboss.org/browse/WFLY-9064 , you have everything to be able to reproduce the original issue easily without running the full test suite. It should help .
It's important to note that the fixes applied by this issue only guarantee that Javassist is compatible. The changes needed for ByteBuddy are more intricate and the ByteBuddy devs are looking into ways to add better support for a security manager enabled environment. , this means the tests under WF will need to explicitly enable Javassist when using ORM 5.3+ until we get a ByteBuddy fix.