You might be thinking of Colorado where they somehow failed to notice that a truck with a bunch of ballots to be sent to voters wasn't unloaded at the post office until people started complaining that they didn't get a ballot. This is quite different from losing voted ballots or not recording a vote correctly.

Georgia lost applications, not ballots. https://www.nytimes.com/2018/10/25/us/politics/senate-house-... However there was an incident in Arkansas where the Democratic candidate for secretary of state was left off the ballot. https://www.arkansasonline.com/news/2018/oct/22/garland-coun...