There’s a bug right now that makes collapsing near-useless (for some users, at least).
Gfy
Mouse is slightly off. First I show that tabs work normally. Then I collapse them and try viewing them. They turn white but don't show the actual content of the tab. https://gfycat.com/SingleTinyCowrieThe ribbon does not properly show when clicking on a tab for the first time when collapsed. If I click on a tab, then click another right after, the second one will show. This issue persisted through a reinstall.
Edit: I’ve noticed that the bug will not occur if a web view is open. If a place file or script is open the ribbon bar will not show, but if a web view is open then it will.