Ive replaced some of my roof lines with some new strip purchased from Ben Brown. Every time I replaced a section,It would work ok on the ground then fail when put back up on the roof. So after some testing Ive worked out that the strip works OK straight from a controller (P2 in this case) however If I plug it in anywhere in my run , ie being fed from older strip, it fails?? plug it back into the controller and it works fine? Am I missing something here? Has anyone else had similar issues. 1/2 my roof depends on this?