Up/Down arrows in function argument hint not clickable

Reproduction steps:
1.Create a Qt GUI Application.
2.In MainWindow::MainWindow use connect fuction, for it is an overloaded function.
3.When type "(" behind "connect",there will be a tip show overloaded function. see assist.jpg.
4.Click the arrow the tip disappear.

Expected result:
When click the arrow, the tip can switch to another overloaded function.
Actual result:
The tip disappear.