actually in total there are 4 places where i have leak

Leak 1
- at my car porch roof
- water mark at the side (connecting part between wall and roof)
- always leaking when rain a bit heavy

Leak 2
- my living room
- water mark in the middle of the roof
- not all the time leak even if heavy rain (maybe depends on the direction?)

Leak 3,4
- at my gutter area
- 1x water mark at the corner, 1x at the middle
- not all the time leak even if heavy rain (maybe depends on the direction?)

Another thing. I have zinc sheet on my roof. i think this will make it more difficult to find the source as the water mark area might not be the actual leaking area