Do not know if it is a bug or not, but it surely bugs me:
There are several functions where you place a (mouse) pointer over a tool slider and then execute an action. For instance, on Mac, "double click" results in zeroing the slider; "Shift + double click" = auto adjustment, etc. Worked rather well in the past. It seems that, after the latest update, LR is much more sensitive to the pointer (mouse) position, and it is almost impossible to execute a click or double click without first moving the slider a point or two. Now, every time I move a slider, it is recorded in history as two moves. Just plain annoying and cluttering the history states.