I recently when rebuilding a conservatory fitted lead flashing in the normal way - secured with lead 'plugs' Then pointed with ready mix said to be suitable for pointing. And just noticed some of it has fallen out. I wetted the bricks before pointing, and it's about 1" deep. All the other pointing I did to the brick 'half' walls of this building, using the same stuff, is fine.
Is there a flexible gunge more suited, or a different mix? Luckily, it's easy to get to so no big deal to do again.