Is there any way to set the app that it should always open the default dashboard at every start even when the app is only in the background and not fully closed?
No, there’s no setting to reset the page being shown. Given your wording I’m guessing you discovered the “remember last page” setting. Depending on what you’re looking to do, you could accomplish this with JavaScript in the frontend, or if you’re looking for quick access to a particular dashboard using the Open Page widget to navigate to a dashboard directly.
Was already expecting this. Was hopping that it always starts with the same dashboard and not with the last visited