The new group wall layout is a little wonky. Feedback is always welcome. If it's not working on your current device, I'd suggest going through the private message dropdown to use your group wall.
In the meantime, what device are you on? Are you using mobile web on a phone or tablet? If so, what device is it and what browser are you on? Or, are you using a desktop/laptop?
I'm using a Notebook Laptop. It's small, and sometimes i get issues with other websites about the screen resolution, but i didn't have that issue before the site was updated. There was a scrolling button i could click on beforehand that would let me see all the group wall posts after clicking on it and holding it down with my mouse while moving it up and down the screen, but there isn't anything like that now at all. I just hope this issue gets fixed soon so no one else has to deal with it.
Also, my browser is Firefox.