Here are some suggestions to resolve the issue:
1. Ensure you have the latest versions of NTFS-3G and FUSE (file system in userspace) installed on your system. You can download them from their official websites or use package managers like Homebrew to update them. You can also try unloading and reloading the FUSE.
2. Go to System Preferences -> Security & Privacy -> General. If you see a message about a blocked system extension, click "Allow" to enable it.
3. Use Disk Utility to check the disk for errors and repair them if necessary. Sometimes disk errors can cause mounting issues.
4. Connect the Seagate GoFlex drive to another USB port on your Mac or attempt to use a different USB cable to rule out hardware issues.
5. The other resort is that you may need to seek further assistance from Seagate support.
6. To enable full read-write access to NTFS drives on macOS, you can use third-party software. Since you have FUSE-based solutions like NTFS-3G, if you run into issues again irritatingly in it, please uninstall NTFS-3G and download another software tool that allows macOS to write to NTFS-formatted drives, iBoysoft NTFS for Mac.
Best NTFS for Mac by iBoysoft
You can also refer to External Hard Drive Not Mounting on Mac, How to Fix It? and How To Completely Uninstall Paragon/Tuxera NTFS For Mac?
