Occasionally, Apple will issue a “quiet” free service option for certain devices that exhibit consistent manufacturing faults. Our local vendor, SolutionKeys, likes to make sure that our community knows about these as soon as they are released so that we can take advantage of these services (should we need them). Please have a look at the most recent one here, to do with Keyboards in some MacBooks and MacBook Pros.
Thanks, Ms. Cassie and Mr. Wind!