Preorder is a messy option re report if used incorectly, you probably need to create a custom report rather than use defaults.
Bare in mind that depending on the report type report may refer to order date or ticket date so simply changing ticket date doesnt cover all outcomes.
Personally never used preorder option and don’t intend to so cant give much in the way of direction on its use.
You just need to redo your reports to not show preorder tickets in your sales. Look at kb.sambapos.com I think it documents how to filter preorders. If not you can try support@sambapos.com