My application gets stuck in QQuickItemPrivate::nextPrevItemInTabFocusChain in certain situations, when trying to navigate along the tab focus chain. Looks like there is an non terminating pingpong between the root item and its last child.

There might be a similar effect, when inverting the child items and navigating forwards - but I didn't check that.

I noticed the problem with Qt 5.6 and 5.10, but I would expect to find it in all Qt5 versions.

Attached is a minimal code snippet, that sets up such a situation. Using the debugger you can easily see what is going on.

On my system ( X11 ) the behavior is Qt::TabFocusAllControls.