要解决Angular 7路由动画只能运行一次的问题，你可以尝试以下代码示例中的解决方法：

1. 在app.module.ts中导入BrowserAnimationsModule：

import { BrowserAnimationsModule } from '@angular/platform-browser/animations';

@NgModule({
  imports: [
    BrowserAnimationsModule
  ],
  ...
})
export class AppModule { }

2. 在组件中定义动画：

import { trigger, transition, style, animate } from '@angular/animations';

@Component({
  ...
  animations: [
    trigger('routeAnimations', [
      transition('HomePage <=> AboutPage', [
        style({ position: 'relative' }),
        query(':enter, :leave', [
          style({
            position: 'absolute',
            top: 0,
            left: 0,
            width: '100%'
          })
        ]),
        query(':enter', [
          style({ left: '-100%' })
        ]),
        query(':leave', animateChild()),
        group([
          query(':leave', [
            animate('300ms ease-out', style({ left: '100%' }))
          ]),
          query(':enter', [
            animate('300ms ease-out', style({ left: '0%' }))
          ])
        ]),
        query(':enter', animateChild()),
      ]),
      transition('* <=> FilterPage', [
        // Define your animation for other routes
      ])
    ])
  ]
})
export class AppComponent { }

3. 在HTML模板中应用动画：

4. 在组件中定义getRouteAnimation方法：

import { RouterOutlet } from '@angular/router';

@Component({ ... })
export class AppComponent {
  getRouteAnimation(outlet: RouterOutlet) {
    return outlet.activatedRouteData.animation;
  }
}

5. 在路由模块中定义动画数据：

import { NgModule } from '@angular/core';
import { RouterModule, Routes } from '@angular/router';

const routes: Routes = [
  { path: '', redirectTo: 'home', pathMatch: 'full' },
  { path: 'home', component: HomePageComponent, data: { animation: 'HomePage' } },
  { path: 'about', component: AboutPageComponent, data: { animation: 'AboutPage' } },
  { path: 'filter', component: FilterPageComponent, data: { animation: 'FilterPage' } },
];

@NgModule({
  imports: [RouterModule.forRoot(routes)],
  exports: [RouterModule]
})
export class AppRoutingModule { }

通过以上步骤，你应该能够解决Angular 7路由动画只能运行一次的问题，并使动画在每次路由导航时都能正常运行。