Yes I know, what I'm trying to say that the rewrite now on the forum is alterned, not just in this two pages.
Another examples:
If I try to refresh the latest discussions in the main page, one time it gives me:
The requested resource was not found.
The second time the refresh goes fine without problems.
If I try to access the tags page, one time it gives me the tags page without problems, the second time it gives me the index.php file out of the flarum folder. It's like that one time it execute the requests with the /flarum path and one time without it.