Boost: Tooltip shows null value

[madepiet]

Expected behaviour

Tooltip: In normal mode, only values != null are displayed.

Actual behaviour

The boost mode does show the tooltip also when the value is null.
This was not the case in version 10.3.3 so the behaviour has changed.

Live demo with steps to reproduce

https://jsfiddle.net/BlackLabel/wgujxm7k/

Product version

v11.0.0

Internal note:
Bisected to f0977ce