I googled lot around related to the following problem: I have a freshly pre-installed Windows 10 on my Dell notebook. When I start to move a window, a blue-colored assistance symbol shows up offering me to maximize the window (see the pic below):
Some kind of Snap Assist feature:
Related to my information it has nothing to do with Snap Assist - I tried to turn it off by that, no success. This blue-colored figure goes with as it's moved and if I drop the window on it accidentally, than the window get maximized (annoying feature - perhaps it's thought out for touchpads).