When debugging on an android device, the default debugger stops at qml breakpoints but not at C++ breakpoints

I can reproduce this with the 'heartrate game' demo, setting breakpoints in main.qml Component.onCompleted:' and in main.cpp line 16.

In 'Run settings' -> 'Debugger Settings', I have checked both 'Enable C++' and 'Enable QML'.

I got around this by: Manage kits -> debugger -> change from the default debugger from:

Android debugger (Multi ABI, NDK 23.1.7779620) LLDB

to:
Android debugger (Multi ABI, NDK 23.1.7779620) GDB

FYI, for more complex projects, once you change from LLDB to GDB,  when you start debugging, you get lots of popup windows reporting SIG33, which is something android does. I ended up turning this off by:
edit -> preferences -> Debugger -> GDB -> uncheck the box labelled "Show a message box when receiving a signal".