As mentioned in the title, what caused it... and the CSS was obtained and stored in the cache.
Now we find that only the subpages linked in the homepage, that is, the first refreshed partial page, can be displayed normally when refreshed for the first time. So the question is, how to force refresh the subpage? Or how to refresh other pages in the route?
Locate new problems and solutions:
How to refresh the entire page in angular?
Whether the css is referenced on the child page or the parent page, check the path
Don’t worry, owner, check if the css is not loaded, try introducing css on the template page~~~