Hello Kechacha!
using the hamburger menu on the left, if you select "PERSONS" you should see a magnifying glass on the right, which let you do a free search.
If you click those 3 points on the top right ("kebab menu style") you should list the persons also by Surname:
the surname listing shows by surname alphabetical order from A to Z even if the persons snippet boxes shows the name before like always.
In case of equal surnames, the order orders alphabetically also the names.
If you click surname again, the order is in a reverse direction, from Z to A.