Drives 64 GB and greater made by SanDisk are formated as exFAT, not FAT32, and will accept file sizes up to 16 EB which is larger than the flash drive itself.
If your drive is FAT32 it is used of counterfeit. If it is exFAT than the problem you are having is not due to the flash drive. Maybe the app you’re using to write to the flash drive.
You’re not writing to the Secure Access system are you?
