trouble changing slider pics

Hi there

wonderful theme for a WP noob like myself, I’m having great difficulty in one element though =(

URL: https://www.etech.com.vu

Basically i want to change the slider images, so that’s straightforward, i login into the WP dashboard,then customize theme,then theme slider options.

the first image is fine, but when i upload a second image of my choosing,it doesn’t reflect in the website,it still shows the default pic (lady)

does anyone know how i can solve this?

much appreciated..

thanks

Ravi