I've been using GS Pro for waypoint flights with a P4 Pro (iPad mini, iOS 10.3.3).  Sometimes I reach a point in the mission layout where I'm not able to add any waypoint actions.  Having selected a waypoint, nothing happens when I tap on waypoint actions.  I can create a new mission and add actions, but on several missions at some point I'm no longer able to.  Is this a bug, or is there some setting that disables waypoint actions?  Any help is appreciated.

Does the issue appear recently? Please upload a short video for better assistance.

Did you already found out the reason why you can't add the actions? I am having the same problems..

I Have the same problem!!!!

In basic setup make sure you have Straight selected for cornering. If Curved is selected you do not have waypoint actions available.