Alert giving value 0


As you can see on the screenshot bellow, I have a series with only one point and an alert on this series with’last point between now and h - 1 is above 90

The point has the right value on the graph (76.11) but when I try the alert, it says that the value of my point is 0.
I can’t figure out why…
Also, if I change my SQL query to have ‘select now() as time, 76.11 as ratio’ it gives me the good value of the point in the alert.

Can someone help me understanding why the vlue on the graph and the value returned by the alert are not the same ?