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?"

• https://support.mozilla.org/en-US/kb/bookmarks-firefox
• https://support.mozilla.org/en-US/kb/use-firefox-sidebar-access-bookmarks-history-synced

@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.