Good shout I went further up the roof and there was moss and dirt. Cleared that and as you can see from the new pic you can now see daylight under the gutter stop end. Guess the water was pooling and seeping under the tiles. Will see how it goes re the ingress of water in the bathroom. I'm in...
I did think that the cap end of the white gutter was really tight to the gulley so if there was any high flow of water this would cause an obstruction.
My house is semi detached and on the join with the neighbouring side it's a 45 degrees extension with a gulley running down it. As you can see from the pics, the gulley edge is under the tile but doesn't seem to have much of a lip on it. Should the lip be higher to combat the increased flow of...