Hi, @johnsonlin, the 404 URL in the HAR file is this:
At Netlify, we will serve one of two files for this this URL:
Because neither of those files exist, the URLs are 404s when requested. I do see that URL working as you browse the site but that is all “client side routing” be a single-page application (SPA).
When you refresh the page though, a real HTTP request is attempted and returns the 404 which is expected.
There is a solution!
The solution is to use the single-page app rule from our documentation. This is the rule below:
/* /index.html 200
Adding that redirect should fix this issue. That rules says, “If a request come in for an invalid URL, redirect that request invisibly (without changing the address in the address bar) back to the main page of the site.”
If it does not fix the issue or if there are any other questions, please let us know.