I suggest a couple of photos, hinge, catch, slider in the edge of the window etc, so people can see your problem.
Chances are, often as not the hinge has failed around the plastic slider, the catches can be adjusted but how it is done depends on the type. Some you move the catch others you rotate the moving stud.
Can't see the striker plate on the frame, but I think you will find the little round latches that protrude and slide when locking can be adjusted by putting a hex key in them and rotating slightly. I think you will find they may on a sort of offset cam to give adjustment.
If the window has dropped and you have to lift slightly to close try undoing the hinge screws a bit and see if you can push the whole thing up slightly.
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