According to many user-published reports — including those collected during the last three months in this Reddit thread — the third-gen Butterfly Switch keyboards aren’t exactly fixed. Rather than keys dying on users, though, the 2018 MacBook Pros and MacBook Airs suffer from a randomly-occuring issue where clicking the space bar enters two spaces.
For example, those suffering under this bug would type like this.
Many had thought the membrane layer under the keys of the 3rd-gen Butterfly keys would protect against failure. I didn’t experience such issues during my 2018 MacBook Air or 2018 15-inch MacBook Pro reviews, nor did it occur during my extended month-long hands on testing with the Retina Air.