LDAP authentication stopped working for one user

public bool IsAuthenticated(string ldap, string usr, string pwd)
        {
            bool authenticated = false;

            try
            {
                DirectoryEntry entry = new DirectoryEntry(ldap, usr, pwd);
                object nativeObject = entry.NativeObject;
                authenticated = true;

            }
            catch (DirectoryServicesCOMException cex)
            {
                _logger.Error("DirectoryServicesCOMException occured");
                _logger.Error(cex, cex.StackTrace);
            }
            catch (Exception ex)
            {
                _logger.Error($"Exception occured: {ex.Message}");
                _logger.Error(ex, ex.StackTrace);
            }
            return authenticated;
        }