My navigation bar in Jira sometimes hide its content (buttons and links) and sometimes not.
The wierd thing though is that it happens on the same page (any page), if i refresh the page sometimes it shows this navigation bar:

while in other times it shows this navigation bar:

*Web Server: Im using Nginx with PageSpeed module.
*Protocol: HTTPS (Cloudflare)
*DB: MariaDB
*Server: CentOS 7