Hi there!
Thanks for your query.
I have checked our demo, the image getting 100% width and height. https://prnt.sc/26oqpmm
You can use the following code in your custom CSS:
#sp-simpleportfolio .sp-simpleportfolio-description .sppb-carousel-extended-item img {
height: auto !important;
}
Hope this will solve the issue for you!
Note: Path towards custom CSS: Extensions>Templates>Styles> Click on your current default template name then choose Template Options. Then find custom CSS within the custom code.
Best Regards