We have several bugs about ehperal messages behaviour. I open meta bug to quick them together since their fixes can be related with each other.
Created attachment 326641 [details]
erroneous hover of ephemeral message when label set to float
when hover over a trigger whose label is set to float, the ephemeral message will not float near the label or mouse pointer unless you include html span elements inside your label.
In this test case, on the first mouseover of the first label, the hint message will align in the appropriate place, however, after you move to the second label and go back to the first, or just go back and forth between the two, you will see that the first label hint hovers to the far side, while the second label hint hovers in the correct place. The only difference between the two labels is a nested html span element in the second label.