WFLYEJB0406: No Jakarta Enterprise Beans found with interface / WFLYEE0047: Incompatible conflicting binding trying to inject @EJB in EAP 7

Issue

• Application failing to deploy, when trying to use @EJB to inject an ejb.

18:02:42,252 ERROR [org.jboss.msc.service.fail] (MSC service thread 1-8) MSC000001: Failed to start service jboss.deployment.subunit."example-app.ear"."example-ejb-module.jar".INSTALL: org.jboss.msc.service.StartException in service jboss.deployment.subunit."example-app.ear"."example-ejb-module.jar".INSTALL: WFLYSRV0153: Failed to process phase INSTALL of subdeployment "example-ejb-module.jar" of deployment "example-app.ear"
...
Caused by: org.jboss.as.server.deployment.DeploymentUnitProcessingException: WFLYEE0052: Failed to install component TestSingleton
    at org.jboss.as.ee.component.deployers.ComponentInstallProcessor.deploy(ComponentInstallProcessor.java:109)
    at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:182)
    ... 8 more
Caused by: org.jboss.as.server.deployment.DeploymentUnitProcessingException: WFLYEJB0406: No Jakarta Enterprise Beans found with interface of type 'examples.ejb.ExampleSingletonBean' for binding test.TestSingleton/singleton
    at org.jboss.as.ejb3.deployment.processors.EjbInjectionSource.getResourceValue(EjbInjectionSource.java:90)
    at org.jboss.as.ee.component.deployers.ComponentInstallProcessor.processBindings(ComponentInstallProcessor.java:261)
    at org.jboss.as.ee.component.deployers.ComponentInstallProcessor.access$000(ComponentInstallProcessor.java:80)
    at org.jboss.as.ee.component.deployers.ComponentInstallProcessor$1.handle(ComponentInstallProcessor.java:213)
    at org.jboss.as.ee.component.ClassDescriptionTraversal.run(ClassDescriptionTraversal.java:54)
    at org.jboss.as.ee.component.deployers.ComponentInstallProcessor.deployComponent(ComponentInstallProcessor.java:216)
    at org.jboss.as.ee.component.deployers.ComponentInstallProcessor.deploy(ComponentInstallProcessor.java:101)
    ... 9 more

This TestSingleton is trying to use @EJB to inject ExampleSingletonBean:

@Startup
@Singleton(name="TestSingleton")
public class TestSingleton {
    @EJB
    private ExampleSingletonBean singleton;

@Startup
@Singleton(name="ExampleSingletonBean")
public class ExampleSingletonBean implements ExampleSingleton

• When hot deploying the application after EAP was started, this error also showed up WFLYEE0047: Incompatible conflicting binding :

ERROR [org.jboss.msc.service.fail] (MSC service thread 1-5) MSC000001: Failed to start service jboss.deployment.subunit."example-app.ear"."example-ejb-module.jar".INSTALL: org.jboss.msc.service.StartException in service jboss.deployment.subunit."example-app.ear"."example-ejb-module.jar".INSTALL: WFLYSRV0153: Failed to process phase INSTALL of subdeployment "example-ejb-module.jar" of deployment "example-app.ear"
...
Caused by: java.lang.IllegalArgumentException: WFLYEE0047: Incompatible conflicting binding at java:jboss/exported/example-app/example-ejb-module/ExampleSLSBBean!examples.ejb.ExampleSLSB source: org.jboss.as.ejb3.deployment.processors.EjbJndiBindingsDeploymentUnitProcessor$2@3f566732
    at org.jboss.as.ee.component.deployers.ModuleJndiBindingProcessor.addJndiBinding(ModuleJndiBindingProcessor.java:300)
    at org.jboss.as.ee.component.deployers.ModuleJndiBindingProcessor.deploy(ModuleJndiBindingProcessor.java:124)
    at org.jboss.as.server.deployment.DeploymentUnitPhaseService.start(DeploymentUnitPhaseService.java:182)
    ... 8 more