We are in the process of migrating our production OTRS system to version 2.4.5 (from 2.3.4). We use AutoIncrement ticket numbering: testing the new version with a migrated copy of our 2.3.4 system's database, tickets appear to be getting assigned ticket numbers that had previously been used, but had been deleted  from the original system in the run up to taking it live.

Is the re-use of previously used but deleted ticket numbers a behaviour that we would expect to see when upgrading the system?

Thanks,
John Barratt