This is a weird one.
Simply adjust the size of the little 3D model that's in the little 3D model view box at the upper left corner of the Shader Forge window, to make it much bigger.
Then, select some text in a code node, and press Ctrl+C to copy the text (not sure what keys you would use on a mac, or if this bug is repeatable on a mac).
As soon as you hit Ctrl+C, it will reset the size of the 3D object view box to its default size, and your view will shift a moderate distance to the right.
It's not the end of the world kind of bug, but it's weird. This is in v1.28.
Customer support service by UserEcho