When you launched into audit mode, Windows was using the build in system admin user "administrator".
When you launched normally and went through OOBE, I believe you are on a normal user.
I believe Discord is normally installed per user, not for every user on the PC. Discord itself documents that its Windows files are stored unders
https://support.discord.com/hc/en-us/articles/209099387--Windows-Installer-Errors
Based on those folders, it tells me installation is in the user profile folder, so the installation is per user.
So, I dont' think this is a glitch. Just download and install Discord again while signed into your normal Windows account.
For future clean installations, Audit Mode is fine for installing drivers and applications that install system-wide, but I would wait until after OOBE to install applications such as Discord that use a per-user installation.