Issues are dissapearing

Hello. Hope you're great.
Wanna know if you had this problem where issues randomly are dissapearing and can't be found from redmine or the database. You can see the correlative numbers of the issues and there you also can notice the ones missing.

We have Redmine-2.5.2-2 from the bitnami bundle running through a MSSQL2008 database. I'm the admin and no one else has access to the database or permissions to delete issues.

Any thoughts are welcome