ERROR: duplicate key value violates unique constraint "installation_category_pkey"

[gonafr]

I'm getting the following error:
ERROR: duplicate key value violates unique constraint "installation_category_pkey"

In 3 days, on a high demand server, this error happened 16029 times.
I think this error has been reported on 2016/Sep/08 in a Jira inside RedHat: https://issues.redhat.com/browse/AEROGEAR-5840

Checking the error stack the error appear at the addInstallation() method on the ClientInstallationServiceImpl class.
ERROR [org.hibernate.engine.jdbc.spi.SqlExceptionHelper] (EJB default - 10) ERROR: duplicate key value violates unique constraint "installation_category_pkey" Detail: Key (installation_id, category_id)=(8248264a-9203-4434-83b6-7d2a85e6f722, 14) already exists. 2021-01-19 08:27:28,108 ERROR [org.jboss.as.ejb3.invocation] (EJB default - 10) WFLYEJB0034: EJB Invocation failed on component ClientInstallationServiceImpl for method public abstract void org.jboss.aerogear.unifiedpush.service.ClientInstallationService.addInstallation(org.jboss.aerogear.unifiedpush.api.Variant,org.jboss.aerogear.unifiedpush.api.Installation): javax.ejb.EJBException: javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: could not execute statement at org.jboss.as.ejb3.tx.CMTTxInterceptor.invokeInOurTx(CMTTxInterceptor.java:246) at org.jboss.as.ejb3.tx.CMTTxInterceptor.required(CMTTxInterceptor.java:362) at org.jboss.as.ejb3.tx.CMTTxInterceptor.processInvocation(CMTTxInterceptor.java:144) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.invocation.InterceptorContext$Invocation.proceed(InterceptorContext.java:509) at org.jboss.weld.module.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:81) at org.jboss.as.weld.ejb.EjbRequestScopeActivationInterceptor.processInvocation(EjbRequestScopeActivationInterceptor.java:89) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.component.interceptors.CurrentInvocationContextInterceptor.processInvocation(CurrentInvocationContextInterceptor.java:41) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.component.invocationmetrics.WaitTimeInterceptor.processInvocation(WaitTimeInterceptor.java:47) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.security.SecurityContextInterceptor.processInvocation(SecurityContextInterceptor.java:100) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.deployment.processors.StartupAwaitInterceptor.processInvocation(StartupAwaitInterceptor.java:22) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.component.interceptors.ShutDownInterceptorFactory$1.processInvocation(ShutDownInterceptorFactory.java:64) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.component.interceptors.LoggingInterceptor.processInvocation(LoggingInterceptor.java:67) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ee.component.NamespaceContextInterceptor.processInvocation(NamespaceContextInterceptor.java:50) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.component.interceptors.AdditionalSetupInterceptor.processInvocation(AdditionalSetupInterceptor.java:54) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.invocation.ContextClassLoaderInterceptor.processInvocation(ContextClassLoaderInterceptor.java:60) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.invocation.InterceptorContext.run(InterceptorContext.java:438) at org.wildfly.security.manager.WildFlySecurityManager.doChecked(WildFlySecurityManager.java:619) at org.jboss.invocation.AccessCheckingInterceptor.processInvocation(AccessCheckingInterceptor.java:57) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.invocation.ChainedInterceptor.processInvocation(ChainedInterceptor.java:53) at org.jboss.as.ee.component.ViewService$View.invoke(ViewService.java:198) at org.jboss.as.ee.component.ViewDescription$1.processInvocation(ViewDescription.java:185) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.component.interceptors.LogDiagnosticContextRecoveryInterceptor.processInvocation(LogDiagnosticContextRecoveryInterceptor.java:82) at org.jboss.invocation.InterceptorContext.proceed(InterceptorContext.java:422) at org.jboss.as.ejb3.component.interceptors.AsyncFutureInterceptorFactory$2$2.runInvocation(AsyncFutureInterceptorFactory.java:152) at org.jboss.as.ejb3.component.interceptors.AsyncInvocationTask.run(AsyncInvocationTask.java:81) at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149) at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624) at java.lang.Thread.run(Thread.java:748) at org.jboss.threads.JBossThread.run(JBossThread.java:485) Caused by: javax.persistence.PersistenceException: org.hibernate.exception.ConstraintViolationException: could not execute statement at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1692) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1602) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.convert(AbstractEntityManagerImpl.java:1608) at org.hibernate.jpa.spi.AbstractEntityManagerImpl.flush(AbstractEntityManagerImpl.java:1303) at org.jboss.as.jpa.container.AbstractEntityManager.flush(AbstractEntityManager.java:459) at org.jboss.aerogear.unifiedpush.jpa.dao.impl.JPABaseDao.update(JPABaseDao.java:78) at org.jboss.aerogear.unifiedpush.service.impl.ClientInstallationServiceImpl.updateInstallation(ClientInstallationServiceImpl.java:179) at org.jboss.aerogear.unifiedpush.service.impl.ClientInstallationServiceImpl.updateInstallation(ClientInstallationServiceImpl.java:197) at org.jboss.aerogear.unifiedpush.service.impl.ClientInstallationServiceImpl.addInstallation(ClientInstallationServiceImpl.java:90)

Any clues of what might be happening?