Window (+ frame) dropping out of position in main frame

[citylover]

Hello, I have a new problem and not sure how to fix. I have a big aluminium window frame with two windows in it, both in their own little frame. The top one, which has an 'arm' on either side as it's open/close mechanism, is dropping on one side a bit, leaving a draughty gap at the top when closed (or as closed as I can get it now). Does anyone know a good local guy/ company that can fix this? Tried to attach a photo but the files too large, if I can work out how to compress it I will add, I'm a bit stone age when I comes to technology unfortunately!

I'd be very grateful for any recommendations.

[se15mum]

We have exactly the same problem with our upvc window as we've had some movement in the bay. I would love to hear any recommendations (I can't currently open the window its moved so much