Hello Kaja,
It is because you have a huge text in the header along with logo which has overlapped the menu items about and projects. You can either decrease the size of logo and text Or just simply increase the spacing above the menu.
You can try this code to increase the space above the menu items. Please add the following code to the Additional Css(Appearance->customize->additional css)
.fullscreen-menu-inside-container {
padding-top: clamp(190px,16.5vw,300px);
}
Please let me know if that worked or not.
Regards,
Sujeet