Very often 1 visit-session are tracked as two visit-sessions.
// config.ini.php
[Tracker]
visit_standard_length = 21600
Very often 1 visit-session are tracked as two visit-sessions.
// config.ini.php
[Tracker]
visit_standard_length = 21600
Which cookie management system are you using? We sometimes see this when a visitor is on your site then accepts the cookies and for some reason the CMS creates a new visit.
Cookieless tracking.