Images failing to load on ios 11 after time

Please forgive my struggle trying to describe this issue. My application works perfectly on Android. On iOS I have been struggling with the following symptom:
The app works perfecting displaying all images correctly. But after some undetermined amount of time (or something) the images no longer render and only show a small square. This is very reproducible simply by starting the application and leaving it running overnight. The next morning the images will not render. Reload the app and everything works correctly.
More details: This behavior is happening to local image assets accessed with

Absolutely nothing fancy at all.
Unfortunately, this is blocking the release. Can anyone help?

“dependencies”: {
@angular/animations”: “5.2.10”,
@angular/common”: “5.2.10”,
@angular/compiler”: “5.2.10”,
@angular/compiler-cli”: “5.2.10”,
@angular/core”: “5.2.10”,
@angular/forms”: “5.2.10”,
@angular/http”: “5.2.10”,
@angular/platform-browser”: “5.2.10”,
@angular/platform-browser-dynamic”: “5.2.10”,
@ionic-native/calendar”: “^4.7.0”,
@ionic-native/core”: “4.7.0”,
@ionic-native/email-composer”: “^4.7.0”,
@ionic-native/image-picker”: “^4.7.0”,
@ionic-native/native-storage”: “^4.7.0”,
@ionic-native/photo-viewer”: “^4.7.0”,
@ionic-native/splash-screen”: “^4.7.0”,
@ionic-native/status-bar”: “4.7.0”,
@ionic/pro”: “^1.0.20”,
@ionic/storage”: “2.1.3”,
@ngx-translate/core”: “^9.1.1”,
@ngx-translate/http-loader”: “^2.0.1”,
“com-sarriaroman-photoviewer”: “^1.1.16”,
“com.synconset.imagepicker”: “~2.1.10”,
“compass-sass-mixins”: “^0.12.7”,
“cordova-android”: “7.0.0”,
“cordova-ios”: “4.5.4”,
“cordova-plugin-calendar”: “^5.0.0”,
“cordova-plugin-device”: “^2.0.2”,
“cordova-plugin-email-composer”: “^0.8.15”,
“cordova-plugin-ionic”: “^4.1.5”,
“cordova-plugin-ionic-keyboard”: “^2.0.5”,
“cordova-plugin-ionic-webview”: “^1.2.0”,
“cordova-plugin-splashscreen”: “^5.0.2”,
“cordova-plugin-statusbar”: “^2.4.2”,
“cordova-plugin-telerik-imagepicker”: “^2.1.10”,
“cordova-plugin-whitelist”: “^1.3.3”,
“ionic-angular”: “3.9.2”,
“ionicons”: “3.0.0”,
“moment”: “^2.22.1”,
“ng2-dragula”: “^1.5.0”,
“rxjs”: “5.5.10”,
“sw-toolbox”: “3.6.0”,
“zone.js”: “0.8.26”
},
“devDependencies”: {
@ionic/app-scripts”: “^3.1.9”,
“typescript”: “~2.6.2”
},
“description”: “Norwex Activity Builder”,
“cordova”: {
“plugins”: {
“cordova-plugin-calendar”: {},
“cordova-plugin-email-composer”: {},
“cordova-plugin-whitelist”: {},
“cordova-plugin-device”: {},
“cordova-plugin-splashscreen”: {},
“cordova-plugin-ionic-webview”: {},
“cordova-plugin-ionic-keyboard”: {},
“com.synconset.imagepicker”: {
“PHOTO_LIBRARY_USAGE_DESCRIPTION”: “Add images to your Why Board!”
},
“com-sarriaroman-photoviewer”: {},
“cordova-plugin-ionic”: {
“APP_ID”: “a485d85b”,
“CHANNEL_NAME”: “Master”,
“UPDATE_METHOD”: “background”,
“WARN_DEBUG”: “true”,
“UPDATE_API”: “https://api.ionicjs.com”,
“MAX_STORE”: “2”
},
“cordova-plugin-statusbar”: {}
},
“platforms”: [
“android”,
“ios”
]
}
}