Screenshot of the issue? And what steps are you doing in the browser.

Hi, where are you pressing Enter? If you are entering a search term or URL in the address bar, you can hold down the '''Alt''' key while pressing Enter to send the request to a new tab. What if you want it to happen automatically without holding down the Alt key? There is a hidden setting for that, and here's how to test it out: (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 '''browser.urlbar.openintab''' and pause while the list is filtered. (3) Double-click the preference to switch the value from false to true If you go ahead and test it out, does it work? ''Note: if you set that to true and you sometimes want the request to go to the same tab, hold down the Alt key while submitting the request.''