If you access the board, and this thread, using Safari on the iPhone, swipe to the top of the thread, and touch the start time (e.g., 1:35 pm for the AAA game, 12:05 pm for the AA game), it doesn't work?
When I do this (iPhone SE, iOS 10.3.3 - I keep this thing up to date), it opens the box score page in a new tab/window. Just tested it now - it opened both the AAA and the AA box scores without any problem.
Now, if I try to open Gameday (by touching on the "Gameday" links in kikutaro's post), I get the message you describe. But that's trying to open Gameday - NOT the box score. The links to the box score work just fine on my iPhone.