React Native AsyncStorage stops working once app is offline

Question

I have a relatively simple app (my first) that needs to display information that is retrieved from a GraphQL query and then stored in AsyncStorage. Everything works fine until you turnoff data/Wifi connections and relaunch the app - it will not load the same local data it did when networking is on. This is the same on a physical or emulated Android device.

There are no data calls except when the user initially sets their details. The app is built with version 2.7.1 of Expo & AWS Amplify. I have wasted several days with this final issue and gotten the same behaviour with Expo SecureStore & Amplify Cache and am loath to go down the route of learning and including Redux on such a simple app...

//import from react native not react
import { AsyncStorage } from 'react-native'

//calling a function as app loads
componentDidMount() {
    this._loadInitialState();
}

//retrieving String from AsyncStorage
_loadInitialState = async () => {
    try {
        const policyNum = await AsyncStorage.getItem('policyNum')
        //...
    } catch {
        //...
    }

//setting state
if (policyNum != null && policyNum != undefined) {
        this.setState({ policyNum: policyNum })
    //...
}

//the original setting of the item
setPolicyDetails = async () => {
    if (this.state.policyNum != null) {
        const policyNumber = this.state.policyNum
        this.state.policyNumSet = true
        try {
            await AsyncStorage.setItem('policyNum', policyNumber)
        } catch (err) { 
        //...
        }
    }
}

Answer 1

Are you storing a string? asyncstorage only can store strings . try using JSON.stringify and JSON.parse

_loadInitialState = async () => {
    try {
        var policyNum = await AsyncStorage.getItem('policyNum')
        policyNum = JSON.parse(policyNum) // converting to original
        //...
    } catch {
        //...
    }

//setting state
if (policyNum != null && policyNum != undefined) {
        this.setState({ policyNum: policyNum })
    //...
}

//the original setting of the item
setPolicyDetails = async () => {
    if (this.state.policyNum != null) {
        const policyNumber = this.state.policyNum
        this.setState({ policyNumSet: true })
        try {
            var policyNumberString = JSON.stringify(policyNumber)
            await AsyncStorage.setItem('policyNum', policyNumberString) //converting to string
        } catch (err) { 
        //...
        }
    }
}