Conservatory leak from 'finial' bolt.

Evening folks.....
Can I ask a quick question regarding a leak in conservatory.

I am doing the clad ceiling project and have covered one glass side at the boundary side.
Thankfully some sort of global upvc cladding shortage has struck my local wickes so I am 10 lengths short of completion. There has been a a leak on and off for a while thought the roof ' finial' I think it's called. Basically I don't have a fan but where that would be in the roof there is a long bolt which screws a solid plastic rose bowl thing in place.
I have noticed this bolt is only finger tight.

I presume this should be tight in order to draw the outside ridge cap thing down. Should this be mega tight and do any experts out there think this will be the likely cause of the leak? Appreciate hard to say for deffo without seeing it.
Glad I hadn't finished the cladding so kinda pleased wickes ran out of cladding so I got time to fix this damn dribble

Trying to upload pics ....please bear with me.

Thanks....
Dirkas.

 

Thanks koolpc. I tightened it then it poured down. Still dripping. Hey ho. Wondered if the cap thing was spongy and retaining water or whether I have a leak along the ridge capping things .
Will get up there and give it all a good sealing.
Cheers.