Could you try this: (1) In a new tab, type or paste '''about:config''' in the address bar and press Enter/Return. Click the button accepting the risk. ''More info on about:config:'' [[Configuration Editor for Firefox]]. ''The moderators would like us to remind you that changes made through this back door aren't fully supported and aren't guaranteed to continue working in the future.'' (2) In the search box in the page, type or paste '''inBack''' and pause while the list is filtered. Firefox should list several preferences. These are the interesting ones: (A) browser.search.context.loadInBackground This determines whether to activate the new search results tab when you right-click a selection and "Search [engine] for [selected text]". Default is "false" = "activate immediately". ''No need to change that for resolving the bookmarks issue.'' (B) browser.tabs.loadBookmarksInBackground When you direct a bookmark to a new tab, this determines whether to activate the new tab immediately or leave it in the background. Default is "false" = "activate immediately". '''''Toggle this one to true either by double-clicking the preference or by clicking the toggle button toward the end of the row.''''' Success? (C) browser.tabs.loadDivertedInBackground A diverted tab is one that the site was sending to a new popup window, but Firefox diverted to a new tab instead. These are treated specially because many sites use popup windows for immediate interaction, but you can treat them like ordinary new tabs. Default is "false" = "activate immediately". ''No need to change that for resolving the bookmarks issue.'' (D) browser.tabs.loadInBackground This is the preference connected to the "When you open a link, image or media in a new tab, switch to it immediately" checkbox on the Settings page. Default is "true" = "leave in the background". ''You can manage this through the Settings page.''