1. How window.history.back() Interacts with a SPA:

When you use window.history.back(), the browser does indeed change the URL in the address bar to return to the previous URL in its history.
However, because this is a SPA, the browser doesn't trigger a full page reload or rerun Angular's initial startup process just because the URL has changed via the history.
Angular's router is supposed to listen for these URL changes (whether they come from a routerLink, programmatic navigation, or the browser's back/forward buttons). When the router detects the URL change, it must identify the corresponding route and render the correct component.
The problem usually occurs when the Angular router fails to properly handle returning to the previous URL, or if the rendered component fails to reset properly.

2. Incorrect Router Configuration:
The route you are returning to may not be correctly defined in your Angular routing configuration. The router doesn't know which component to display for that specific URL.
3. Missing or Incorrect Route Parameters:
If the previous route required parameters (e.g., /details/:id), and these parameters are not correctly present or interpreted when returning via history, the router may fail to match the route.