Question Storage capacity is showing different then the folder sizes

[ItsEnraged]

I have something I have never came across before. I was installing some games to an NVME SSD (1TB) I have, and it told me it was full. I didn't think this was the case, because I didn't have too many games installed on the drive. I opened the drive, highlighted all folders (hidden, system, and all can be seen) and selected properties to get the size of the folders. The total says 505gb. Windows is saying that I have 104gb left out of 931gb. Somewhere there seems to be about 300gb missing. I was going to delete everything and reformat, but didn't want to go through the trouble just yet. I was wondering if anyone knew what would cause the reporting error on the drive. I have google'd about as much as I could stand. I don't know the best keywords to find something related to this. The few posts I have found want me to download software of course and Im not doing that. At least not from unknown sites. Just looking for a possible answer on what could be causing this before formatting it. Its just a storage drive for games. Nothing more. No OS or anything. It wont take me too long to place everything back on here, but I was hoping to not have to do it at all.

Thanks in advance. My schedule is kind of odd so I will get on here when I can to reply to anyone that may try to help.

 

[USAFRet]

Install and run either WinDirStat, or WizTree.

Run as Administrator, selecting only the drive in question.
Post a screencap here.

Also, a screencap of your Disk Management window.