We are on cloudways, and I know i have to use the Omit Port matches code into wp-config.php and that was already done to even get redirects to work.
However, we had to put in redirects for every possible variation for the URL. As an example:
If I create a redirect from "something.com/about/" to "something.com/new-about/", when I access to the page "something.com/about/", it redirects properly. But If access to "something.com/about" it gives a 404 error.
So, we need to create two redirects, one with the trailing at the end of the URL and other without it.