I did considered formatting the external drive to the GSX compatible format, however, if I do this I will lose all the other files in the external drive (the files are about 800GB worth of info). Is there any way I can solve my problem without losing the data in the external drive or losing my money?
What if your 800GB of External drive FAILS? Anybody using a PC in 2023 should have learned by now, it's just irresponsible to keep only one copy of any data you care for without some kind of backup. External drives for backup are cheap today, so there's no excuse for not having one.
Because, of course, having a backup media will allow you to REFORMAT the external drive without any issues (provided you made a backup, of course).
And no, NTFS is not the "GSX Format", it's Windows own NATIVE File system and, it's especially dangerous NOT to use it on an External drive because, one of the (many) things that makes NTFS better and safer to use, is a much bigger reliability against file corruption due to the drive turning off while data is being written on it.
While the "drive turning itself off" is extremely rare on an internal drive, it's quite common to happen on an External drive, if the cable disconnects for any reason. So, I'd say NTFS is even more useful and safe on an External Drive.
The issue is, most External drivers ships formatted in ExFat, so you can use them without reformatting on PC, Mac, Linux. But ExFat doesn't support lots of Windows-specific features, in this case Symbolic links which we need to use, so for a Windows-only usage, it's way better to use the proper Windows Filesystem.