Redirecting iTunes Backup folder odd behavior

I have followed the instructions to redirect iTunes backups, and everything appears to be correct. When I start an iPhone backup, it creates a file in my new intended target folder on an SDXC card. The initial backup behavior that I am used to where the full status bar is blue for a while happens as normal, but then when it would normally start at the beginning of the status bar and progress along with the backup, it stops with no error, and the file is under 200MB and does not show up in the list of device backups. A backup of this phone (from recent previous experience) should be at least 50GB.

I am baffled, because if It didn't work at all, then I would know something was off with my mklink, but I delete the small backup and start over and the same thing happens.