Jupyter 5.7.8 notebook on localhost tooltip not working at all (Shift + Tab not working)

I have search for this problem for few hours and both of the solution that I found are useless for me, I am using MacOS Mojave, when my cursor focus on a function, in edit mode and I press (Shift + Tab) it did'n happen anything, I have look at the command shortcut in the help tab, to display a tooltip are Shift + Tab, but why is it useless for my case ?

Reproduce the problem with Jupyter Notebook 5.7.8 on macOS Mojave using a localhost notebook. Start by checking the documented Shift+Tab shortcut in edit mode and whether focusing a function triggers a tooltip. Done means the tooltip appears when the shortcut is pressed, or the cause of its absence is documented.

Written by the indexing model from the issue text.