1991 300sl soft top rod is not connected,see pic please

[rp930]

new owner of 1991 300 sl, I think I have identified the part to be 129-770-21-14 on epc. I'm asking for help to determine why it came loose. when i lower the top it tries to fold towards front instead of back. please see pics. I only put the top up twice, so I don't know if this broke loose when I did it or if was already done. need to find out why this happened so I can repair. thanks good members