Total size storage wrong (300MB) and can't see files under HFS+ macOS Extended through Wi-Fi

Hey guys, I have just formated “my passport wireless pro 3TB” to HFS+ (macOS extended) in High Sierra, it works through USB perfectly. But when I try to disconnect from USB and turn wi-fi on, the drive is mounted with only 300MB in total size and I can’t see my files and folders there. Has anyone experienced this same issue?

Sounds like you are having file system issue if you are only seeing 300MB in total size. Try running a scanDisk first.