@Stanisable @FirefoxNightly Because they are non-hierarchical, untreed, they are no replacement for my beloved #Sidebery, but i agree the recent improvements of them in is commendable, not least their fix two days ago of group collapsing/expanding.

@vyskocilm Aha!

groups can be collapsed & expanded, that function is broken in vertical tabs

#FirefoxNightly gets updates 2x/day. The 2nd one today fixed this, so now the groups do behave well in #VerticalTabs

@vyskocilm It doesn't have tree structure as you said, but also, whilst in horizontal mode the tab groups can be collapsed & expanded, that function is broken in vertical tabs. Furthermore, in vertical [my preference, as a longtime TST --> #Sidebery user] guise, the vertical padding between tabs is ginormous, such that only a small number of tabs fully consumes the column height & triggers the scroll bar, whereas in Sidebery the same tabs occupy a fraction of the space. There's so many other problems & omissions as well. The Devs have a long long way to go before their native VTs will ever viably replace my Sidebery.

Btw, i use #FirefoxNightly, whose #VerticalTabs deployment is slightly more advanced than in vanilla .

@danirod I use #ZenBrowser [several months], but with various profiles. My main profile uses #Sidebery, not the native #VerticalTabs & #Workspaces. One of my other profiles does use all the native features & no Sidebery, but though i frequently try it, atm it's still too primitive for my tastes compared to the power of Sidebery. Fwiw, in that other profile, i have occasionally experienced what you described, & iirc various peeps have mentioned it in subreddit posts.

@mzeinali Fwiw, i've been monitoring their progress for months, in my #FirefoxNightly. It's still extremely primitive, & barely functional. The tab groups are merely single-tier [ie, there is no nesting nor tree structure], & though they now can be collapsed in the horizontal tabs bar, once you switch to the #VerticalTabs bar the collapse function fails. They are still so far behind the sophistication of #TreeStyleTab & especially #Sidebery AOs that i fear they'll never catch up... meaning this long-missing native function/feature will never become viable for me.

Atm my hopes are slenderly vested in #ZenBrowser whose Dev @zenbrowser months ago promised that fully nested native tree tabs were on their development path [https://l.opnxng.com/r/zen_browser/comments/1eqqzlt/the_one_feature_that_will_win_me_over/lhv19c4/?context=3#lhv19c4]. Until then, in all my Foxes, it remains #Sidebery all the way.

@fatboy Pity imo that the new tab groups still can't yet be collapsed in #VerticalTabs, only horizontal.