Expo SDK 38 + custom iOS Expo Client + MapView Issue

Hi All,

I am currently developing an expo application which uses the MapView component to render the map. It works as expected on both ios and android while developing using the expo harness however when I try to use the customer iOS harness to enable background location updates everything seems to work fine except the map now loading. It just appears grey. All polylines and markers seem to work as expected and I can pan as normal.
I followed the instructions in similar posts but nothing have worked for me thus far. See below my current module versions:
Expo SDK 38
react-native-maps: 0.27.1

See below the object structure in my app.json file.

	"expo": {
		"name": "**",
		"slug": "mobileApp",
		"privacy": "public",
		"platforms": [
		"version": "1.0.0",
		"orientation": "portrait",
		"icon": "./assets/images/logo.png",
		"splash": {
			"image": "./assets/images/splash.png",
			"resizeMode": "contain",
			"backgroundColor": "#ffffff"
		"updates": {
			"fallbackToCacheTimeout": 0
		"assetBundlePatterns": [
		"ios": {
			"supportsTablet": true,
			"config": {
				"googleSignIn": {
					"reservedClientId": "**"
				"googleMapsApiKey": "**"
			"bundleIdentifier": "**",
			"infoPlist": {
				"UIBackgroundModes": ["location"]
		"android": {
			"package": "**",
			"versionCode": 1,
			"config": {
				"googleMaps": {
					"apiKey": "**"
			"googleServicesFile": "**",
		"hooks": {
			"postPublish": [
					"file": "**",
					"config": {
						"organization": "**",
						"project": "**",
						"authToken": "**"

When creating the restrict token I took these steps:

  1. Enabled Maps SDK for iOS
  2. Created a new API credential
  3. Set the application restriction to iOS apps
  4. Set the bundle identifiers to that found in the app.json file
  5. Added Maps SDK for iOS for the API restriction

Feel free to reach out for any additional information.


I don’t thins will solve your issue, but i think you’re missing a “buildNumber: ?” field from your iOS section.

I had an issue getting my map to work, but it turned out I used the wrong fingerprint for the GMaps key, where i think i used the one obtained through the keystore, but i needed the one used by Google as i use Google Signing.

Hope this helps.

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