Flash Messages/states Are Lost From One Module To Another?

I have the root application, and a HybridAuth module.

If I set a flash message in one of the HybridAuth module’s controller, that flash is only visible in that module. If I redirect the user to the root application the flash is not displayed there.

I’ve checked and both uses the same statekeyprefix, but when I print_r($_SESSION), they differ. Hybrid auth contains the flashes, and the root module doesn’t.

Why does this happen?