I have inherited this home as part of an estate and I am also inheriting the issues. Had I been involved with this endeavor I would have raised hell, but here I am.
A new metal roof was installed 5+ years ago by a local "handyman" (it's a small coastal town in the Gulf of Mexico.) This is a 2nd home, so although the original owner knew about a leak, they were unaware of the extent.
The home has an addition, where the pitched roof transitions into a flat roof. The owner raised issue that the roof was leaking and the "handyman" made a transition to the flat roof (B in pictures). While they were installing the transition, these idiots were lazy AF and just bent up the existing panels and shoved a flat transition piece in place and sort of screwed back down (A). It continued to leak so they used spray insulation foam under the high ridges and sort of put roof tar along it as well. It was good enough for the owner at the time to call it good.
Now it's my issues; the spay foam as expected failed, the tar was illogical for a few reasons. The transition piece they installed sloped back from the flat part of the roof to the pitched part of the roof (pooled, wouldn't drain), so a family friend installed an additional extension (C). It helped but there is still a leak. I added strip foam the best I could to the sloped part of the roof (A-ish) and siliconed along its edge since it slopes towards it. The leak has slowed significantly, but it still exists.
I don't know my best approach. Rip up the bent panels/affected area and redo that section properly (water barrier was never used from my observation). Use a sealant tape or coating to cover the affected area to see if that fixes it. Redo the entire roof. Something I haven't even considered?
I work in the trades, so likely I am going to do this myself. The idea of the "easy fix" sounds great since I don't live in the area, but I also appreciate just doing it right. I've mulled this over so much that I don't know my best approach. The pictures are at various times, but show the over all scope.