First of all the good news: Apple allows a warranty repair. Important: If one of the mentioned parts of your MacBoo has been repaired before, you are still affected.
According to a source of macrumors, the problem is that if either the SSD or the motherboard is defective, both components have to be replaced.
Apple has identified a specific population of MacBook Pro (13-inch, 2017, Two Thunderbolt 3 Ports) units requiring both solid state drives and the main logic board to be replaced when either has a functional failure.
A message will appear when either the solid state drive or the main logic board part number is added to the repair of an identified MacBook Pro system. The message will indicate both the SSD and MLB must be replaced when either component has a functional failure.
So if you have a model that has already had one of the two parts replaced, you should contact Apple and ask again. It seems that both components are so strongly connected that a fault of one affects the other.
