To use Secure Access you would have to sign in to it so if you didn’t you aren’t writing to it. 
If the drive is showing it is formatted as FAT32 reformat it to exFAT. I believe Windows supports Converting the Drive to exFAT so you shouldn’t have to backup everything first. If I’m wrong copy the files and folders on the flash drive to your harddrive, reformat it, then copy everything back.
You do not have to nuke the drive to reformat it so don’t get carried away with the process or use an app from Google. And do NOT format it as NTFS.
