I agree that in this case it might seems not consistent, but labels are hidden because they could overlap with something else, for example when it comes to that top point that you mentioned, the label is hidden because it could overlap y axis label. Check this example with disabled y axis labels. The data label of top point shows correctly when hovering Allocated Budget
You might be thinking, why it works fine for Allocated Budget
and for Actual Spending
not. The reason is pretty much the same, one of series detect that labels could overlap with other. It might seem that there is enough space to show them, but in reality, even though labels of the other series are hidden, they are still present in the DOM. For this specific chart I would suggest setting allowOverlap: true for series that have enough space to show all labels, and false for series like Actual test
Another suggestion that you might want to consider is increasing actual chart area. With more space the problem could be significantly reduced, and now Actual test
series is hardly seen anyway.
Feel free to ask any further questions.