Hi,
indeed weird.
Please inside custom CSS of template add below code
@media (max-width: 540px) {
.com-spsimpleportfolio.view-item #sp-page-builder .sppb-row-container {max-width: 480px;}
}
@media (max-width: 480px) {
.com-spsimpleportfolio.view-item #sp-page-builder .sppb-row-container {max-width: 440px;}
}
@media (max-width: 380px) {
.com-spsimpleportfolio.view-item #sp-page-builder .sppb-row-container {max-width: 360px;}
}