Eriba 530
I’ve had a small leak about 30cm to the left of my wardrobe, with a slow series of drops of water running down the wall having emerged from under where the wall cupboard meets the wall.
This is directly underneath a 2cm stretch of the awning rail where the bead of black mastic has thinned and seems to have detached from the paintwork.
First noticed during snow.
Any advice will be gladly welcomed!

I have just discovered a similar problem and have followed other advice on here and bought 45mm wide a white replacement mastic roll from Amazon:

W4 Wide Mastic Sealing Strip - White, 5m x 45mm - £16.99 with Prime next day delivery.

This width is easier to apply, trimming off the excess after installation.