When setting dragEnabled to true in the LayerList widget, the layers with listMode='hide-children' do not display properly in the layerList, the "open" chevron is still visible. Without dragEnabled it works
See pen ..
https://codepen.io/christophesuter/pen/PogwbeE
Thanks for posting and letting us know @ChristopheSuter
@ChristopheSuter this should be fixed in tomorrow night's patch for the 4.29 release.