lbSetTooltip does not create an actual tooltip on the listbox when hovering over the list item. The tooltip is set and can be retrieved from lbTooltip but still does not appear.
i.e.
_listBox lbSetTooltip [0, "test"]; systemChat format ["%1",_listBox lbTooltip 0];
Will return "test" but the list won't show the tooltip.
https://sqfbin.com/exatehuqehigacorovoq
I've left a snippet of the code. Relevant functions are towards the bottom and MAZ_populateListbox and MAZ_inventoryGUI.
virtualItemsCreated will be formatted as [ [ "Name", "Tooltip", "Icon", {Code}, buy, sell ] ]
In this example, the tooltip is the string "Repair Kit used for restoring vehicles to near full health."
MAZ_populateListbox is passed the listbox from uiNamespace & the player, and the tooltip is retrieved from the array, then set as the tooltip. I don't think I've messed up syntax for this and there shouldn't be any UI elements overlapping the listbox.
I've tried this in MP & SP environments
Edit: From the snippet provided run the entire code and open your inventory to see the virtual inventory.
I recognize the prior repro is very large, here is a significantly shorter version.
https://sqfbin.com/epuzukezoqodecejowem
Edit: Description
As you can see from running the repro, when you hover over the Test Entry there is no tooltip, but when the function that adds the tooltip is called, it will systemChat the current tooltip for the index, "Test Tooltip".
So the game recognizes that the tooltip exists and that its correct, but the tooltip doesn't display.