This is the case when the Matomo install has only one site. Then select "Visitors -> Real-time" in the reporting menu <img width="543" alt="image" src="https://user-images.githubusercontent.com/273120/194149152-88210989-c135-44d2-b8ac-f7cd7efd5b1e.png"> The segment selector should be aligned with the card below and be moved a few pixels to the left.