title: Angular 12: injected service is undefined
body: <p>When trying to inject one service into another - both beeing providedIn: 'root', the injected service is undefined:</p>
  <pre><code>@Injectable({
    providedIn: 'root',
  })
  export class MessageService {
  }
  
  @Injectable({
    providedIn: 'root'
  })
  export class ColDefService {
  
    tableId: string;
  
    constructor(
      private valueGetterService: ValueGetterService,
      private messageService: MessageService
    ) {
    }
  
  }
  </code></pre>
  <p>This is the error I am getting.</p>
  <pre><code>    core.js:6456 ERROR TypeError: Cannot read properties of undefined (reading 'messageService')
      at getAngebotGemeindNameAndNr (value-getter.service.ts:97)
      at ExpressionService.push.52107.ExpressionService.evaluate (ag-grid-community.cjs.js:32392)
      at ValueService.push.52107.ValueService.executeValueGetter (ag-grid-community.cjs.js:28459)
      at ValueService.push.52107.ValueService.getValue (ag-grid-community.cjs.js:28288)
      at CellComp.push.52107.CellComp.getValue (ag-grid-community.cjs.js:21414)
      at CellComp.push.52107.CellComp.getValueAndFormat (ag-grid-community.cjs.js:21397)
      at new CellComp (ag-grid-community.cjs.js:20699)
      at RowComp.push.52107.RowComp.newCellComp (ag-grid-community.cjs.js:42687)
      at ag-grid-community.cjs.js:42641
      at Array.forEach (&lt;anonymous&gt;)
  </code></pre>