与Ivy一起仅在Angular 8中工作localhost：4000 / index.html

Question

我有一个带有angular（v8.2.9）Universal（v8.1.1）和Ivy的项目。
我使用以下命令构建并运行服务器端。

npm run build:ssr && npm run serve:ssr

构建并成功运行，但是在浏览器中输入localhost:4000时显示白页，而控制台和服务器中没有错误。
成功进入localhost:4000/index.html网站后才能加载并正常工作。
为什么要在网址中添加index.html？

{
  "name": "amyar24site-ivy",
  "version": "1.4.0",
  "scripts": {
    "ng": "ng",
    "start": "ng serve",
    "build": "ng build",
    "test": "ng test",
    "lint": "ng lint",
    "e2e": "ng e2e",
    "compile:server": "webpack --config webpack.server.config.js --progress --colors",
    "serve:ssr": "node dist/server",
    "build:ssr": "npm run build:client-and-server-bundles && npm run compile:server",
    "build:client-and-server-bundles": "ng build --prod && ng run amyar24siteIvy:server:production --bundleDependencies all"
  },
  "private": true,
  "dependencies": {
    "@angular/animations": "~8.2.9",
    "@angular/common": "~8.2.9",
    "@angular/compiler": "~8.2.9",
    "@angular/core": "~8.2.9",
    "@angular/forms": "~8.2.9",
    "@angular/http": "~7.2.15",
    "@angular/platform-browser": "~8.2.9",
    "@angular/platform-browser-dynamic": "~8.2.9",
    "@angular/platform-server": "~8.2.9",
    "@angular/router": "~8.2.9",
    "@fortawesome/fontawesome-free": "5.11.2",
    "@ng-select/ng-select": "^3.0.7",
    "@nguniversal/express-engine": "^8.1.1",
    "@nguniversal/module-map-ngfactory-loader": "^8.1.1",
    "@ngx-translate/core": "^11.0.1",
    "@ngx-translate/http-loader": "^4.0.0",
    "bootstrap": "^4.3.1",
    "compression": "^1.7.4",
    "core-js": "^3.2.1",
    "express": "^4.17.1",
    "hover.css": "^2.3.2",
    "intersection-observer": "^0.7.0",
    "memory-cache": "^0.2.0",
    "moment": "2.24.0",
    "moment-jalaali": "0.8.3",
    "ng-circle-progress": "^1.5.1",
    "ng-in-viewport": "^6.0.3",
    "ng-lazyload-image": "^6.1.0",
    "ngx-bootstrap": "^5.2.0",
    "ngx-cookie-service": "^2.2.0",
    "ngx-device-detector": "^1.3.11",
    "rxjs": "~6.5.3",
    "tslib": "^1.10.0",
    "zone.js": "~0.10.2"
  },
  "devDependencies": {
    "@angular-devkit/build-angular": "~0.803.8",
    "@angular/cli": "~8.3.8",
    "@angular/compiler-cli": "~8.2.9",
    "@angular/language-service": "~8.2.9",
    "@types/node": "~12.7.12",
    "@types/jasmine": "~3.4.2",
    "@types/jasminewd2": "~2.0.8",
    "codelyzer": "~5.1.2",
    "jasmine-core": "~3.5.0",
    "jasmine-spec-reporter": "~4.2.1",
    "karma": "~4.3.0",
    "karma-chrome-launcher": "~3.1.0",
    "karma-coverage-istanbul-reporter": "~2.1.0",
    "karma-jasmine": "~2.0.1",
    "karma-jasmine-html-reporter": "^1.4.2",
    "protractor": "~5.4.2",
    "ts-loader": "^6.2.0",
    "ts-node": "~8.4.1",
    "tslint": "~5.20.0",
    "typescript": "~3.5.3",
    "webpack-cli": "^3.3.9"
  }
}