I've run into this problem multiple times where I can't figure out why the heck the WMC PVR addon for Kodi gives me the "Recorded TV folder not found" error. Then I started created separate users in Windows to access the share.
I finally realized it's because there's an issue with how it builds the smb:// connection string. Since it's typically formatted as "user:password@host". So if your password contains an @, it might look like "user:pass1@@host", and it fails.
Is there a way to fix this so it supports passwords with @ characters in them?