cordova-plugin-googlemaps: ios app crash when using addMarkerCluster

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cordova information: (run $> cordova plugin list)

com.googlemaps.ios 2.5.0 "Google Maps SDK for iOS"
cordova-plugin-device 1.1.4 "Device"
cordova-plugin-facebook4 1.9.1 "Facebook Connect"
cordova-plugin-google-analytics 1.8.3 "Google Universal Analytics Plugin"
cordova-plugin-googlemaps 2.1.2-beta-20171122-1040 "cordova-plugin-googlemaps"
cordova-plugin-googleplus 5.1.1 "Google SignIn"
cordova-plugin-ionic-webview 1.1.16 "cordova-plugin-ionic-webview"
cordova-plugin-splashscreen 4.0.3 "Splashscreen"
cordova-plugin-statusbar 2.3.0 "StatusBar"
cordova-plugin-whitelist 1.3.1 "Whitelist"
ionic-plugin-keyboard 2.2.1 "Keyboard"

If you use @ionic-native/google-maps, please tell the package.json (only @ionic-native/core and @ionic-native/google-maps are fine mostly) “@ionic-native/core”: “^4.3.3”, “@ionic-native/google-maps”: “^4.3.3”,

Current behavior:

Hello, I have an error. when I use addMarkerCluster. It draws markers but when I use a custom image for a marker at that time app crash with below error. it happens only ios. somebody can help this issue??

Expected behavior:

Screen capture or video record:

Related code, data or error log (please format your code or data):

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[NSCache setObject:forKey:cost:]: attempt to insert nil value (key: http:/localhost:8080/var/containers/Bundle/Application/1E01FEE3-8DDB-4796-8CB6-196E881CA368/udc2.app/www/index.html#/menu/./assets/img/map/m1.png)'