Debug breakpoint + application combobox open freezes qtcreator

This problem happens at least since 2 years ago QtCreator versions.

While debugging a widgets application, if a breakpoint is hit while an application qcombobox is presenting it's list, qtcreator freezes and most of the window manager also freezes (you can move the mouse but neither the keyboard nor mouse clicks workd).

Reproduced with QtCreator 4.13 + Qt5.15.0 GCC 64bit, with the attached example:

 - Set a breakpoint in the onTimeout slot

 - Start debugging the application

 - show the combo list and move up-down waiting for the breakpoint to be reached

 - when the breakpoint is reached, qtcreator freezes

To solve the problem, you have to kill the gdb process (reproduced with gdb-multiarch and gdb) by switching to a terminal (e.g. CTRL+ALT+F6, login, kill the process, return to your terminal).