Sunroof leak. Drain pipes appear unblocked

After a damp patch on the headliner and seeing that the rear drain pipe from the sun roof was badly kinked I thought I may have resolved the water leak.

With the snow today, I noticed that the water is running from the back of the roof cut out and it's dripping over the Black sun roof assembly, near to the silver torx screw in the picture.

I am going to double check all drain holes again as things have been ok up untill now and this came about suddenly.

Any pointers please?