Have you reviewed both the share permissions and the folder permissions?
This Powershell script will report on user shares.
Get-SmbShare | Where-Object -Property Name -NotLike '*$' | foreach { # exclude hidden and administrative shares
"----------------------------------------------------------------"
"Share permissions for {0}." -f $_.Name
$_ | Get-SmbShareAccess | Format-Table -Property AccountName, AccessControlType, AccessRight
""
"NTFS folder permissions on {0}." -f $_.Path
(Get-Acl -Path $_.Path ).Access | Format-Table -Property IdentityReference, AccessControlType, FileSystemRights -AutoSize
}