The Sony HDR-AZ1 action camcorder forces you to use a microSDXC card for recording XAVC-S video instead of MP4. If you have a UHS-I card that has excellent write speed but is 32GB or smaller, the camera will block you from recording anything in XAVC-S format, restricting you to 28 Mbps or lower video. Fortunately, there’s a great workaround which will still trigger the SDXC warning but will unblock recording.
Put your microSDHC card into a computer. Reformat the card as exFAT instead of FAT32. Done! You will get beeped at and warned because the card still isn’t an actual SDXC card, but you can now record at 50 Mbps and enjoy the higher quality without buying another memory card!