I am working on the project in the timeline and use “Split At Playhead” somewhere on the clip 2 times. On the resulting part of th clip I use the function “separate audio” in the right click menu. After that I delete the resultig audio track by pressing the delete button on the marked audio track (just to remove any unwanted audio from the video track).
After doing that I am NOT able to use “Split At Playhead” anymore, it does nothing.
I use Shotcut version 19.02.28 (german version) and windows 10 pro version 1809 build 17763.379