The window is a side hinged upvc. When the window is closed, there is a gap at the top left corner. It's the corner from the top and the lock side (handle side) f the window. It's in the spare room, and I only really just noticed it. The window doesn't have a riser in the window. Could it have buckled the hinges? Order some new hinges and a riser block and replace? Thank you for the help.