I personally don't think it's a Weld problem, but you can try to enable debug log level for Weld in WF - see Weld: Documentation. Maybe you can describe your app little bit more. It is vanilla WildFly 12.0.0.Final right?
Maybe this is related to Hibernate [HV-1410] CDI Integration uses deprecated API - Hibernate JIRA .
Yes this is a vanilla WildFly 12.0.0.Final started with standalone-full.xml configuration. The database is Oracle Database 11g Express Edition Release 22.214.171.124.0 - 64bit
The OS is openSUSE Leap 42.3 with kernel 4.4.120-45.
The application is more a proof of concept which I took from https://blog.holisticon.de/wp-content/uploads/2011/10/ticket2rock-2.0-dist.zip
This application should cover all aspects of JEE. It was developped and tested under JBoss 6.1.0 Final. l migrated the application to WildFly.