Here are some steps to investigate why emails are being sent to the wrong folders in Outlook:

1. Check the settings of any mail rules being used in Outlook.
2. Disable any unnecessary email rules to avoid triggering a false move to another folder.
3. Check the settings for the Junk Mail and Phishing filters.
4. Disable the Junk Mail filter if it is to blame for moving emails to the wrong folder.
5. Delete and recreate the PST file if problems continue.