Front lens cover/curtain latch not closing

So I have dismantled the camera using video instructions due to the lens error and was trying to see if the flex cable is broken, which it is (will order one). I came down to stripping the who camera also because the lens wouldnt close all the way to the end and have come to realize that at the front lens there is a latch which I can move with my finger and the protective cover closes, but when I connect it with the focus barrel it still wont go all the way to the end and that is a problem.

So I either preferably fix this somehow or in the end I will be forced to brake the latch so the lens goes all the way to the end of the barrel route and quite possibly there wont be a problem apart from not having the cover closed at any time.

Video that I found that shows this exact problem is :
replaces the lens part with another one

so I just uploaded my video : curtain latch issue

Its this IRING BARRIER thingy.

for recording and info for all purposes I leave this picture of the front cap - it takes some serious effort to take out - after this someone can really replace the lens

Any ideas greatly appreciated !!