For users who are already familiar with one-off searches, and want to perform an immediate search (without the need for suggestions), the new behavior adds an extra step:

-- Old one-off behavior: --

1. Enter search term in address bar
2. Press one-off search button (e.g. DuckDuckGo)
   => Search is executed immediately on DuckDuckGo.

-- New one-off behavior: --

1. Enter search term in address bar
2. Press one-off search button (e.g. DuckDuckGo)
   (suggestions from DuckDuckGo are shown)
3. Press ENTER or click first entry
   => Search is executed on DuckDuckGo.

This may be inconvenient and may lower the number of searches actually performed by the user. Also, the legacy search bar performs immediate one-off searches as well, but not every user has this bar visible.

Therefore, it would be great to offer users the choice how these one-off buttons behave in the address bar: (a) show suggestions first, or (b) search immediately?
This preference could be added under about:preferences#search. Default could be set to the new behavior.
When a user clicks an one-off button first without entering a search term, suggestions can be shown as usual, irrespective of this preference.

The team working on this feature discussed similar concerns at length. As a result, we slightly changed the one-off keyboard shortcuts to support both kinds of behaviour. Users can now press Shift when selecting a one-off button to execute a search immediately. We thought this strikes a good balance: we expect users who want to perform a search immediately are more likely to be power users who are willing to memorize a keyboard shortcut, whereas the new default behaviour makes more sense to general users. Adding a pref increases the maintenance cost of address bar code. I suspect this will be a WONTFIX, but I'll discuss this with UX one more time before closing this.

(In reply to Harry Twyford [:harry] from comment #1)

Users can now press Shift when selecting a one-off button to execute a search immediately. We thought this strikes a good balance: we expect users who want to perform a search immediately are more likely to be power users who are willing to memorize a keyboard shortcut, whereas the new default behaviour makes more sense to general users.

Thank you for the fast reply. I'm very happy to see you guys took this use case into account, and provided a shortcut!
This way we can have the best of both worlds (suggestions per search engine OR immediate search) without having to switch a preference :)
Great solution.

Have a nice Sunday!

I spoke with UX and we're happy with the Shift override being the solution here. We're going to mention the override in the 83 release notes.

I just discovered this bug on updating to ESR 91 branch, and I'm at a loss as to why this decision was made. Why in the world would anyone find the one-click search behavior confusing? I don't need the change my search after I clicked the button, I clicked the button because I want to search! Now I click them repeatedly wondering why it doesn't do anything. Yes, I can learn to hold shift, or press enter afterwards, but I honestly don't understand what problem this solves in the first place.

Ok, I realize I missed the part about search suggestions. I've never liked the concept so I always turn those off right away. But even with them enabled it's still a disruptive change and I'm surprised more people haven't said something. Like, is it really intuitive to think that people will start typing something, then click one of those buttons expecting to get suggestions rather than have it just search what they've typed? It's just hard for me to imagine that anyone was expecting that. The current behavior feels broken and I'm finding it hard to unlearn habits formed over more than a decade using Firefox.

(In reply to Harrison S from comment #9)

I'm surprised more people haven't said something.

In [Firefox Reddit](https://www.reddit.com/r/firefox], there had been many discussions on this broken behavior.

The current behavior feels broken and I'm finding it hard to unlearn habits formed over more than a decade using Firefox.

This is the reason why I'm advocating for Firefox to integrate Redditor aveyo's userscript to bring back single-click search functionality to Firefox.

I don't understand why Firefox WONTFIX this.

Just throwing in my opinion here that I agree with the other commenters -- I think the old behaviour is more intuitive for novices, not the other way around. I can live with the shift workaround but I would prefer the old behaviour, and I don't think this is an opinion which is specific to "power users". I think any kind of user including novices would find the new behaviour more surprising and confusing than the old behaviour.