Problem with Angular in production

Hi everyone,
I have an Angular 7 webApp in which I use fileSaver to download files from a server. In development mode it works correctly; but when I build in production I have this error in the console:
ERROR ReferenceError: file_saver_1 is not defined

I've tried to update the package to the latest version but the problem still persist.
My code is:
`
import {saveAs as importedSaveAs} from "file-saver";
// other imports
@Component({
selector: 'app-agenzie-files',
templateUrl: './agenzie-files.component.html',
styleUrls: ['./agenzie-files.component.css']
})
export class AgenzieFilesComponent implements OnInit {

// functions and variables definition
// Download function:
downloadFile(file: any) {
this.agencyService.downloadFile(this.user.agency['id'], file.id)
.subscribe(blob => {
importedSaveAs(blob, file.url);
}, error => {
this.messageService.add({severity: 'error', summary: 'Attenzione', detail: 'Errore durante il download del file'});
})
}
`
My package.json is:
`"dependencies": {
"@agm/core": "^1.0.0",
"@angular-material-extensions/link-preview": "^1.0.2",
"@angular/animations": "^7.2.15",
"@angular/cdk": "^7.3.4",
"@angular/common": "7.2.15",
"@angular/compiler": "7.2.15",
"@angular/core": "7.2.15",
"@angular/forms": "7.2.15",
"@angular/http": "^7.2.15",
"@angular/material": "^7.2.15",
"@angular/platform-browser": "7.2.15",
"@angular/platform-browser-dynamic": "7.2.15",
"@angular/router": "7.2.1",
"@ng-bootstrap/ng-bootstrap": "^4.0.1",
"angular-mgl-timeline": "^0.3.0",
"angular2-csv": "0.2.5",
"bower": "^1.8.4",
"chart.js": "^2.7.2",
"core-js": "^2.5.4",
"file-saver": "^2.0.5",
"font-awesome": "^4.7.0",
"hammerjs": "^2.0.8",
"jspdf": "^1.3.5",
"ngx-currency": "^2.0.2",
"ngx-gallery": "^4.1.2",
"node-sass": "^4.13.1",
"popper.js": "^1.14.4",
"primeicons": "^1.0.0",
"primeng": "^8.0.3",
"quill": "^1.3.7",
"rxjs": "^6.3.3",
"rxjs-tslint": "^0.1.8",
"tslib": "^1.9.0",
"zone.js": "^0.9.1"
},
"devDependencies": {
"@angular-devkit/build-angular": "^0.10.0",
"@angular/cli": "7.3.9",
"@angular/compiler-cli": "7.2.9",
"@fortawesome/fontawesome-free": "^5.9.0",
"@types/file-saver": "^2.0.1",
"@types/googlemaps": "^3.30.11",
"@types/jasmine": "latest",
"@types/jquery": "^3.2.7",
"@types/node": "latest",
"codelyzer": "latest",
"jasmine-core": "latest",
"jasmine-spec-reporter": "latest",
"karma": "latest",
"karma-chrome-launcher": "latest",
"karma-cli": "latest",
"karma-coverage-istanbul-reporter": "latest",
"karma-jasmine": "latest",
"karma-jasmine-html-reporter": "latest",
"moment": "~2.24.0",
"protractor": "latest",
"ts-node": "latest",
"tslint": "latest",
"typescript": "3.2.2",
"webpack": "^4.4.1"
}`

Is there a way to solve this?