This is a Windows limitation issue
When running the editor through VS debug mode, any breakpoint that is set in the class used as the Default pawn class in world settings will be ignored when playing in editor
1. Open UE4Editor (any project)
2. Add code to project based on Pawn (MyPawn)
3. In MyPawn.cpp add a breakpoint to the BeginPlay function
4. Press F5 to run in debug mode.
5. In the editor, create custom game mode blueprint
6. In world settings, set GameMode Override to custom game mode
7. Set Default Pawn Class to MyPawn
The PIE session will start up and run normally
BeginPlay breakpoint is triggered when the pawn is created.
Head over to the existing Questions & Answers thread and let us know what's up.