Hi Nicole

Has it bowed vertically or along the length of the window ?

It's the window leaf itself that has bowed. Have attached couple of images that hopefully explain it better.

It varies with each window but a lot of them have just warped all kinds of ways.

The one below is probably a bit hard to see but has bowed in the middle.

Hi

You can try resetting the hinges or purchase a new one.

Good luck

Andrew