There’s a horizontal scrollbar, when setting default gutenberg blocks to full width.
You might not see this on the mac, because the scrollbar is only visible, when you scroll.
But on Linux and Windows it’s visible and caused by
.no-sidebar .entry-content .alignfull {
max-width: 100vw;
}
I don’t see a fix for this with this method. I don’t apply the default width to the container but to the items inside the container.
You can test it by yourself by setting the layout without sidebar