Methos generate in org.hibernate.id.enhanced.OptimizerFactory$PooledLoOptimizer classs is not synchronized

Receiving multiple primary key constraint violation exceptions when using SequenceStyleGenerator with optimizer parameter set to pooled-lo. Looking into the source code I found that the generate mathod for the new PooledLoOptimizer is not synchronized. After switching to PooledOptimizer (which has synchronized generate method) every thing works fine.