Does Hibernate Optimistic Locking not work across different JVMs?

Question

We are using Optimistic Locking with JPA and it seems to work perfectly within each multi-threaded service no matter how many threads we add, but when two services running as separate apps are updating the same columns in a table they overwrite each other (dirty reads). Is Hibernate optimistic locking not guaranteed to work across separate JVMs? I've had a hard time finding any info on this.

We are using JPA with hibernate under the hood. Optimistic locking is working, at least between the threads inside each service, I can see it tripping exceptions and trying in the retry listener i added.

Here is some code

@Transactional
@Retryable(value = {Exception.class}, maxAttemptsExpression  = "${locking.max.retry.count:30}",
        backoff = @Backoff(delayExpression = "${locking.retry.sleep.time:10}"),
                listeners = "accountUpdateRetryListener")
public void balancesAndAmtsUpdate(TransactionSet transactionSet) {

       // new entity versions are picked up in here
        mapTransactionsToAccounts(transactionSet);
        groupAccounts(transactionSet);

        // update Accounts
        transactionSet.getAccountPostingAggregators().forEach( agg -> accountUpdate(agg, transactionSet));

        transactionSet.getNettingAggregators().forEach( agg -> {
            if (transactionSet.getDigestForPosting()) {
                accountNetTotalsUpdate(agg);
            }
            accountsNetSourceUpdate(transactionSet, agg);
        });
}