By default any URL on my website will end with a trailing slash.

So if I publish a post or page, the URL will end with a "/".

But I came across a weird situation where I hit publish but the URL with "/" works but without "/" does not work. And when I clear the cache on the WordPress website. both URLS work. with or without trailing slash. And the browser will automatically redirect/change the URL to end with a slash, even if I forgot to put "/" at the end of the URL.

I was reading this article to see properly configure my rewrite rules.

If anyone can help me understand what this issue could be.

It looks like cache issue, but could it be a rewrite rules issue?

Hosted on AWS Lightsail, Bitnami WordPress stack.