I had some Toasts in my project that displayed perfectly. However after adding some new Labels to my form the Toasts popped up underneath the new objects.
I fixed the issue by deleting and replacing all of the Toasts.
George and team: I would have thought the toasts should always be on top of all other controls even if they were added after the Toast control.
The Toast control is part of Bootstrap, so its behaviour depends on how they implemented it.
But here’s hint: you don’t need to delete and add controls again to change their position in the hierarchy. You can use the up and down arrows in the Project Explorer to reorder your controls: