Screws came out of crank bay window and won't screw back in

Hello - I have a 7 bay window with 2 windows on the each outer edge that crank open. On one of the windows, the 3 screws came out of the control arm. However, the screws won't stay in if you screw them back in. It seems there is nothing behind the holes on the window to keep the screws from coming right back out. I've highlighted in the photos the control arm and the holes. Any suggestions would be greatly appreciated!

Thanks for your reply. I'm unable to access the inside of the frame due to it being fully enclosed.
I'm wondering if a slight larger screw/threads would help. Although I'm sure there is a lot of tension at that point.

Thanks Paul, good idea. I'll give that a try!