app.executeCommand(app.findMenuCommandId("Solid...")) doesn't work right?

Hey guys,

I'm tring to use app.executeCommand(app.findMenuCommandId("Solid...")) to add a solid layer to active comp. But it only add a solid layer to the project panel, instead of adding the solid layer to both project panel and active comp.

It works fine when I use this method to add camera, null or shape layer to active comp.

What should I do?

PS, I don't want to use addSolid() method.