macOS: Unable to resize/move app window, title bar stuck underneath Menu bar
The easiest way I've found to bring a window back from under the Menu bar is to resize the window by pressing and holding the shift key and grabbing the left or right side edge of the window and dragging the mouse inwards towards the center of the window.

This resizes all four sides of the window at the same time, thus making it smaller and bringing the top of the window out from under the Menu bar.

You can then afterwards move and or resize the window as wanted on the screen.