Tooltip throws JavaScript error on hovering different targets

[Dimitar-Goshev]

Bug report

Tooltip throws JavaScript error on hovering different targets - Cannot read property 'split' of undefined

Regression since 2021.1.330 - 279cff4#diff-a3e60418bb56f3900808c888dd7bd92f192e42bff696345dfe44025a6c2aa470R499

Reproduction of the problem

1. Go to https://demos.telerik.com/kendo-ui/tooltip/template
2. Hover the first target until the tooltip is visible.
3. Move the mouse down away from the target.
4. Move the mouse up over the first target again and wait for the tooltip to be visible.
5. Move the mouse to the second target.

Current behavior

Cannot read property 'split' of undefined is thrown and the tooltip does NOT appear on the second target

Expected/desired behavior

No JS error and the tooltip appears on the second target

Environment

• Kendo UI version: 2021.1.330
• Browser: all