This effect can possbily be caused by several factors:
Cause 1
It is possible that your PST file is corrupted, check and repair the profiles and the PST file (s). We recommend " scanpst ".
Cause 2
Please check if your PST file is registered under Start / Control Panel / Mail / data file. If not, select your Outlook PST file and confirm with "OK." Then select the added PST file as default and restart Outlook again.
Cause 3
If the profile still does not appear, please create a new profile under Start / Control Panel / Mail / profiles and add your PST file into the newly created Outlook profile. How to create a new profile see here.