If the tooltip is positioned "auto right", then it assumes that its own left + width must be less than the parent width, otherwise it switches to the alternate position:

placement == 'right'  && pos.right + actualWidth      > parentDim.width ? 'left'

However that's not actually true because it ignores the position of the parent (specifically its left offset). Thus it's easy for the tooltip to think there's not enough space when there is.

For example, if you look at the attached screenshot you can see that:

pos.right: 807.75
actualWidth: 191
parentDim.width: 483
parentDim.left: 694.75
parentDim.right: 1177.75

The tooltip should be to the right of the "Add/Remove" button, and clearly there is space: pos.right + actualWidth = 999, while parentDim.right = 1177. However the calculation uses parentDim.width instead of parentDim.right, ignoring the left offset of the parent, so it thinks there isn't enough space.