Undesired pause after App.Run()

Good morning!

based on the ROOT tutorial for plotting data from text files, I made a compile version. But each time it runs, it waits with a blank canvas, until I click somewhere in it with the mouse, then it plots. Is app.Run() waiting for something?

The code is very short can be seen here https://github.com/xaratustrah/simplot together with an example text file for plotting:


For the moment I see nothing wrong in your code.
Try to add:
c->Modified(); c->Update();
right after the line:

c->Update(); did the magic.

many thanks.