You can revert to old grid in about:config - browser.newtabpage.activity-stream.nova.enabled (set it to false).
Starting with the current version 151.0.1, on the Firefox Home page, the shortcuts got shifted all the way to the bottom of the screen. The shortcuts used to be closer to the middle of the screen. When I zoom out, the position of the shortcuts can go up, but the text and icons get smaller so I can't see them as well. There is a lot of blank space on the top half of the screen. The Firefox logo is taking up space. I never had this problem before. The size and position of the icons were fine in all previous versions. You can also see this when adding additional rows of shortcuts. The Firefox icon stays in the middle and the shortcuts get added to the bottom and the homepage has a scroll bar instead of all the icons going up to utilize the blank space.
