Presumably after an update to GNOME Shell, 'Put Windows' extension stopped working.
This was only discovered after trying to put a window into a corner (upper leftmost) of the screen using Super+7 (numeric keypad). The GNOME Shell Extension website - Installed extensions showed ERROR in the place where the extension is turned ON or OFF.
How can I fix this issue?
This was reported on the GNOME website with a support ticket and has been resolved.