It’s worse than that, actually. In your sample doc on the grouped table, if you hit enter on the last row of the Type 1 group, the new focus cell jumps all the way to the bottom of the table (which the user wouldn’t even see if the table ran off the screen). Then, after clicking away from the newly created cell with focus, the newly created row jumps back into its proper grouped position.
I don’t recall this behavior existing previously, so maybe it’s newly introduced?
I was running into a similar issue yesterday that had to do with cell focus within a grouped table. It caused a moderate headache that I had to go back and fix manually. Basically, I was copying text in one grouped cell to paste into another grouped cell. Upon clicking away from the cell where text was being copied (removing focus from that cell) and clicking onto the cell to receive the pasted text (putting focus on that cell), the text in the cell where text was copied from got deleted. That empty grouped cell caused the row to jump elsewhere in the table. Because of the size of the table, I didn’t see any of this behavior taking place until after I had already made a pretty big mess!!
So, yeah, something seems to have changed with the behavior of grouped tables…