Hi Daniel,
You’ve set the post’s content container to contained which will remove the paddings.
There’re 2 places you can check:
1. Go to the post editor, check the layout metabox, if you’ve set the content container to contained there, revert it back to default.
https://docs.generatepress.com/article/layout-metabox-overview/#where-is-it
2. Go to appearance > elements, check if there’s a layout element assigned to posts and if it’s set to contained, if so, revert it back to default.
https://docs.generatepress.com/article/layout-element-overview/