The Start Menu has two different views that you can open apps from; the apps’ list, and the pinned tiles of apps that you frequently use. In both cases, when you click on an app, the app opens and the Start Menu closes automatically because it assumes you only wanted to open that one app. If you want to open multiple apps, you can keep the Start Menu open by pressing and holding the Windows key.
Keep Start Menu open
This is a simple enough trick that works in both the apps’ list view and the pinned tiles view. It’s not very well known because Microsoft has changed the keyboard shortcut that was used to keep Start Menu open. On older versions of Windows i.e. on Windows 7, holding down the Shift key did the trick. On Windows 10, it’s the Windows key on your keyboard.
When you open apps this way, they appear to open in the ‘background’ which basically means the windows are never forced into focus. The Start Menu is always in focus and you can continue to click tiles, and/or browse the apps’ list.
To be clear, you need to tap the Windows key once, and then release it. The Start Menu will not open until you release the Windows key. Once the Start Menu is open, you have to press and hold the Windows key and then click the tiles or apps in the list to open them and also keep the Start Menu open.
If you want the Start Menu to remain open without holding down the Windows key there is, unfortunately, no way to get it to do that. The Action Center can be kept open until you manually dismiss it by editing the Windows registry but there’s no such hack that works for the Start Menu.
You can look into apps that modify the Start Menu and perhaps one of them will do the trick. You do want to take into consideration if something this small is worth running an entire app over. The full screen version of the Start Menu acts the same way i.e., it will automatically close when you click on a tile or app. If you want to keep it open and have apps open in the background, you’re going to have to hold down the Windows key.
This isn’t a change in functionality. The Start Menu always automatically dismissed after a user clicked an item on it. The only change is how it’s kept open.