Drag n drop tab to bookmark folder fails
In Firefox, one can drag'n'drop a tab to the bookmarks toolbar to create a bookmark. During the drag, If one hovers the pointer over a folder in the bookmarks toolbar, the folder is supposed to open so you can put the newly created bookmark inside the folder.
This behavior has been failing a lot for me lately: the folder doesn't open, so dropping the tab doesn't create a bookmark. - The behavior is erratic: right now it works for some tabs and fails for others; - Drag'n'drop to the bookmarks toolbar outside a folder still works; - Drag'n'drop to the bookmarks sidebar, inside a folder or not, still works.
NB: I'm pretty sure it's a bug, but I never created a Mozilla Bugzilla issue before so I decided to see what happens here first.
Browser: 122.0 (64-bit) OS: Ubuntu 22.04 LTS
Alla svar (7)
Go to about:support in the address bar and check the value of "Window Protocol".
Try setting the environment variable MOZ_ENABLE_WAYLAND=1.
Does it still happen with the flatpak version?
Does it make a difference if you already have opened this folder in the current session?
You can drag the Bookmarks Menu button 
that shows the bookmarks in a drop-down list and drag the Library button that gives access to recent bookmarks and history from the Customize palette to the Navigation Toolbar.
The Bookmarks Menu button has a "View bookmarks sidebar" menu item.
See "How do I add the Bookmarks Menu button to the toolbar?"
@zeroknight Window Protocol: Wayland I tried to start Firefox with `env MOZ_ENABLE_WAYLAND=1 /snap/bin/firefox` anyway but same erratic behavior. I have not tried with Flatpak for lack of time.
@cor-el If by "already have opened" you mean clicked on it to display its content, no, it doesn't affect the behavior. I am well aware of workarounds, thanks, but I wanted to report that bug because it affects UX.
Does it still happen if you set MOZ_ENABLE_WAYLAND=0?
Instead of dragging the tab, try dragging the link from the padlock icon in the address bar. Tabs have a lot of baggage associated with them while links are a lot simpler.
How about using OBS to create a video and show the issue.
@zeroknight It does seem to work better with the link from the padlock, thanks for the workaround. @jonzn4SUSE Here you go: https://alternatiba.simoni.pm/s/YaxTqrb4cjYXYp2 You can see that I try 3 folders. From left to right: the first one always works, the second one sometimes works, the third one never works. This behavior is not consistent: some tabs works with all folders, and another time I will have that problem with other folders.