Fedizens on #Matrix ..
If you had trouble with missing rooms in #Element-Web then I have good news.
The Element team has been really busy with creating a fix, even working on Sunday. It was #security issue, as explained in a blog post that was just published.
You should update your Element client asap.
https://element.io/blog/element-web-desktop-1-11-4-a-security-update-deferred-dms-and-more/
(I have some more things to check, as #Android mobile apps of Element and #FluffyChat also displayed the wrong number of rooms, but #Firefox is a go)