Gopro subreddit daily has people posting issues with their camera complaining about the SD card. In all instances they've bought a "genuine" card on Amazon from the official seller, but probably received a fake one due to commingling.

The brand hit from this must be massive, with the amount of people now avoiding Amazon. But perhaps it won't matter with their size, most people won't have any other options anyways. For me, it was counterfeit dental stuff that made me quit buying from Amazon. A faulty SD card is annoying, stuff I put in my body is no-go.