"Search with DuckDuckGo" in private window works only if "Show autocomplete in address bar" is enabled

[Tonev]

Description

The Search with DuckDuckGo option in private window works only if the Show autocomplete in address bar option is enabled. If the Show autocomplete in address bar option is disabled, all searches in private window go through user's default search engine, regardless of the Search with DuckDuckGo preference.

Additionally, the Learn more link next to the Search with DuckDuckGo option redirects to a page where users are asked to sign in to Brave Software.

Steps to Reproduce

1. Go to brave://settings/appearance.
2. Disable Show autocomplete in address bar.
3. Open a private window and enable Search with DuckDuckGo, and perform a search.

Actual result:

The search will go through the default search engine.

Expected result:

The search should go through DuckDuckGo.

Reproduces how often:

Easily

Brave version (brave://version info)

Brave | 1.28.105 Chromium: 92.0.4515.131 (Official Build) (64-bit) -- | -- Revision | 6b8d6c56ce21e38a72f7c4becb5abc1fa5134f29-refs/branch-heads/4515@{#1933} OS | Windows 7 Service Pack 1 (Build 7601) JavaScript | V8 9.2.230.22 User Agent | Mozilla/5.0 (Windows NT 6.1; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/92.0.4515.131 Safari/537.36 Command Line | "C:\Program Files\BraveSoftware\Brave-Browser\Application\brave.exe" --enable-dom-distiller --disable-domain-reliability --no-pings --origin-trial-public-key=bYUKPJoPnCxeNvu72j4EmPuK7tr1PAC7SHh8ld9Mw3E=,fMS4mpO6buLQ/QMd+zJmxzty/VQ6B1EUZqoCU04zoRU= --sync-url=https://sync-v2.brave.com/v2 --lso-url=https://no-thanks.invalid --variations-server-url=https://variations.brave.com/seed --enable-features=LegacyTLSEnforced,WebUIDarkMode,PrefetchPrivacyChanges,ReducedReferrerGranularity,PasswordImport,AutoupgradeMixedContent,SafetyTip,WinrtGeolocationImplementation --disable-features=AutofillServerCommunication,FledgeInterestGroups,HandwritingRecognitionWebPlatformApi,FlocIdComputedEventLogging,HandwritingRecognitionWebPlatformApiFinch,InterestCohortFeaturePolicy,NotificationTriggers,WebOTP,IdleDetection,PrivacySandboxSettings,FederatedLearningOfCohorts,TextFragmentAnchor,EnableProfilePickerOnStartup,SubresourceWebBundles,NetworkTimeServiceQuerying,LangClientHintHeader,LiveCaption,DirectSockets,TrustTokens,SignedExchangeSubresourcePrefetch,EnablePasswordsAccountStorage,FledgeInterestGroupAPI,AutofillEnableAccountWalletStorage,InterestCohortAPIOriginTrial,FirstPartySets,SignedExchangePrefetchCacheForNavigations --flag-switches-begin --enable-features=LegacyTLSEnforced,WebUIDarkMode,PrefetchPrivacyChanges,ReducedReferrerGranularity,PasswordImport,AutoupgradeMixedContent,SafetyTip,WinrtGeolocationImplementation,EphemeralStorage --flag-switches-end Executable Path | C:\Program Files\BraveSoftware\Brave-Browser\Application\brave.exe Profile Path | C:\Users\User\AppData\Local\BraveSoftware\Brave-Browser\User Data\Default Variations | AdRewardsStudy:NextPaymentDayEphemeralStorageStudy:EnabledNativeCosmeticFilteringStudy:EnabledPermissionLifetimeReleaseStudy:EnabledSpeedreaderReleaseStudy:Disabled

Version/Channel Information:

• Can you reproduce this issue with the current release? Yes
• Can you reproduce this issue with the beta channel? Yes
• Can you reproduce this issue with the nightly channel? Yes

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? No
• Does the issue resolve itself when disabling Brave Rewards? N/A
• Is the issue reproducible on the latest version of Chrome? N/A

Miscellaneous Information:

[SarveshMD]

This is something important. Please look after this issue.

[SarveshMD]

I still wonder how you found that disabling "Show autocomplete in address bar" causes the issue 😅✌️

[Tonev]

I accidentally found out Search with DuckDuckGo wasn't working properly in my daily user profile while testing various scenarios for a user in Brave Community - https://community.brave.com/t/private-window-search-defaults-to-ddg-even-when-another-search-engine-is-set-as-default/275775.

I created another user profile so I could determine whether the issue was related to my daily user profile in some way, and it turned out there was something wrong with my daily user profile. So, in order to find out what was wrong with my daily user profile, I simply began changing Brave's default settings in the new user profile until the Search with DuckDuckGo option broke.

[SarveshMD]

Great !