I’m getting same issues when using alignfull.
I understand what you mean about setting pages to be full width, but thats not practical on some sites and will undo a lot of formatting.
My work around is to put
overflow-x: hidden;
on html selector.
Is there any other way we can fix this without having to change all pages to full width and then have to correct any formatting issues that arise on each page?
Maybe adjusting .alignfull that appears in/wp-content/themes/generatepress/assets/css/main.min.css
.no-sidebar .entry-content .alignfull {
margin-left: calc(-100vw / 2 + 100% / 2);
margin-right: calc(-100vw / 2 + 100% / 2);
max-width: 100vw;
width: auto;
}