With 3242 and 3243 on several occasions the info box stopped being updated with metrics or kerning changes. As the image shows, while the O is active the AE info box shows.
It happened to me twice when resuming after I put my Mac to sleep. It happened a third time, when resuming after I had the Glyphs windows hidden for a while, to do something else.
(Edit: It happened a 4th time, when I resumed work after posting this message. I discovered I can revive the info box by selecting a different tab, and then going back.)