Hi,
I just updated from version 7.1 to version 7.9 with no problems in the logs.
When I enter jira and update the screen, the menus appear and disappear without following an apparent pattern.
here can see that the menus have dappeared

Here the menus work fine:

I have seen that the difference between one page and another is this style.
When the menu appears:

When the menu not appears:

I have performed the following actions:
- I have entered addon safe mode
- I updated the browsers.
- I have reviewed the console and have only seen a couple of warnings about dropdown deprecados, but it seems that it is a common message among users.
- I was looking for the error in this forum...but i havent found anything
Can you help me? 
Regards.