Moví mi base de datos local al nivel gratuito de mLab y recibo un error que no recibí antes. ParallelSaveError: Can't save() the same doc multiple times in parallel

El error se captura desde la línea user.save() . ¿Podría echar un vistazo y mostrar cómo solucionarlo? Estoy tan perdido...

 // Confirm password. // Execs after requiresAuth permission resolver. const confirmPassword = ({ user, inputs: { password } }) => { // Validate args. validate([required, isLength], 'PASSWORD', password) // Required for graphql. Expects a promise. return new Promise((resolve, reject) => user.comparePassword(password, (err, isMatch) => { if (err) return reject(err) if (!isMatch) return reject(error('CONFIRM_PASSWORD_FAILED')) return resolve(user) }) ) }

 // Compare submitted plain text password with the salted and hashed version. UserSchema.methods.comparePassword = function(candidatePassword, callback) { return bcrypt.compare(candidatePassword, this.password, (err, isMatch) => { if (isMatch) { this.account.authStrikes = 0 this.account.lastConfirm = Date.now() } else { this.account.authStrikes += 1 if (this.account.authStrikes === 3) { this.account.status = 'locked' require('../resolvers/auth') .createUnlockAccountToken({ userId: this._id }) } } return this.save() .then(() => callback(null, isMatch)) .catch(err => callback(err)) }) }