Do you use any custom userChrome.css file?

Did you place flexible space items on the toolbar? You can check that in customize mode and drag them to the Customize palette.

• https://support.mozilla.org/en-US/kb/customize-firefox-controls-buttons-and-toolbars

@TyDraniu Nope none.

@cor-el Nope I haven't used any flexible space.

Try to go to the CUstomize palette and click Restore defaults.

Try to go to the CUstomize palette and click Restore defaults.

This method only work for your current session You can actually do the same thing just by putting "elements of bookmark panel"? or something like that in there (idk how its called in english sry) the one with the star in a box icon

This was mentioned in the community discussion forum (quote) Firefox 110.0.1 will cause about a 500px wide gap at the left end of the Bookmarks Toolbar if the user has removed the "Bookmarks Toolbar Items" control. If you are testing, launch a new window to see the change.

The suggested workaround for this on Reddit (example) is:

(1) Return Bookmarks Toolbar Items to the bar (2) Delete any bookmarks (for some users, it might be only "Getting Started") (3) Right-click > uncheck "Show Other Bookmarks"

After that, Bookmarks Toolbar Items stays blank and works like a giant flexible space.

This will be fixed in a future Firefox release, currently version 112. Related bug report, if you want to follow it: Bug 1819980 110.0.1 misplaced icons in toolbars with no "Bookmark toolbar items"]

(1) Return Bookmarks Toolbar Items to the bar

This seemed to have fixed it for me and the problem doesn't reoccur.

Thanks for posting that (1) Return Bookmarks Toolbar Items to the bar resolved the problem. By the way, bug 1819980 will now be fixed in Firefox version 111, which is scheduled for release on March 14.