Roof leak at soil pipe

[Barrysh]

Hi rain is leaking into my loft space around the soil pipe where it exits the pitched roof of my house. It is particularly noticable during heavy rain. I'm no builder but a not bad DIYer. I have taken the concrete tiles off from around the pipe and the lead slate appears good. I have bent the back of the lead slate up, as seen on Youtube video and all seems ok. My query is, if water is getting through the roof, higher up, the felt is there to take it down to the gutter. However the felt is cut away all around the pipe and as the pipe is at the bottom of the roof any rain that gets under the tiles will exit here and not into the gutter. Sorry if this seems too simplistic but thats the way it appears to me. I have just repointed all the ridge tiles although they weren't too bad so I'm just waiting for more heavy rain to test it. Could always use a hosepipe to test it I suppose. Thanks, Barry