Flickering and rapid switching between displayed thread in debugger

Debugging testQThread in /tests/manual/debugger/simple/simple_test_app.cpp can sometimes lead to the interface flickering and rapidly switching between threads to display.

I can trigger it pretty consistently by having breakpoints on lines 4219 and 4229 (BREAK_HERE and the last line in run()) and continuing until I reach the BREAK_HERE breakpoint. Then expanding this can lead to the flickering behavior.

I attached a short video showing the visual result (proper screen recording didn't work :/ )