I have a 90mm downpipe which for some reason flows into a 120mm pipe into the ground (this part is under a small deck) and (I assume) stormwater OSD tank. The gap has been sealed when built with some kind of putty (see gray in photo). Something has moved or just age and the putty has cracked around the wider 120mm circumference. Online searching has not revealed any kind of PVC adapter in the size 90 to 120mm. Also it is in an awkward corner. Can anyone suggest any kind of PVC adapter? or should I just replace the putty with something like Aqua knead https://www.bunnings.com.au/selleys-50g-knead-it-aqua-epoxy-putty_p1230080
It leaks very close to a corner of the house and I need to stop the leaking
