UBlock Origin not working in Preview Tab on Edge Android

[Saksham-9]

Prerequisites

• I verified that this is not a filter list issue. Report any issues with filter lists or broken website functionality in the uAssets issue tracker.
• This is NOT a YouTube, Facebook or Twitch report. These sites MUST be reported by clicking their respective links.
• I performed a cursory search of the issue tracker to avoid opening a duplicate issue.
• The issue is not present after disabling uBO in the browser.
• I checked the documentation to understand that the issue I am reporting is not normal behavior.

I tried to reproduce the issue when...

• uBO is the only extension.
• using a new, unmodified browser profile.

Description

UBlock Origin works correctly in normal browsing mode on Edge for Android. However, it does not work in the Preview tab (Edge tab preview page or link preview feature). Other extensions seem to function normally in this mode, so it appears specific to UBlock Origin.

Screenshots

Details

Device & Version: OS: Android 11 Browser: Microsoft Edge Stable - 143.0.3650.125 (Official build) (64-bit)

Additional context:

• Other extensions function normally in Preview tab.
• The issue seems specific to UBlock Origin.
• This affects user experience for ad-blocking in the tab preview feature for all webpages.

A specific URL where the issue occurs.

https://www.indiatoday.in/

Steps to Reproduce

1. Install UBlock Origin from the Microsoft Edge Add-ons store on Edge Android.
2. Open a website in normal mode → UBlock Origin works as expected.
3. Open a link in the Preview tab (tap and hold a link or use tab preview).
4. Notice that ads/trackers are not blocked, and UBlock Origin appears inactive.

Expected behavior

UBlock Origin should work in the Preview tab just as it does in normal browsing mode.

Actual behavior

Doesn't work in preview tab of any website.

Configuration

Details

uBlock Origin: 1.68.0
Chromium Mobile: 143
filterset (summary):
 network: 184790
 cosmetic: 144700
 scriptlet: 40180
 html: 0
listset (total-discarded, last-updated):
 added:
  https://raw.githubusercontent.com/brave/adblock-lists/refs/heads/master/brave-lists/yt-shorts.txt: 15-0, 2d.5h.5m
  adguard-cookies: 36516-78, 2d.8h.55m
  ublock-cookies-adguard: 5314-75, 2d.5h.5m
  fanboy-cookiemonster: 44981-3610, 4d.7h.8m
  ublock-cookies-easylist: 5314-5314, 2d.5h.5m
  easylist-annoyances: 5014-122, 4d.7h.8m
  easylist-chat: 257-0, 7d.10h
  easylist-newsletters: 8920-29, 4d.22h.25m
  easylist-notifications: 2439-5, 4d.22h.25m
  dpollock-0: 11774-661, 5h.59m
  IND-0: 14883-21, 8h.10m
 default:
  user-filters: 5-0, never
  ublock-filters: 44278-88, 2h.29m Δ
  ublock-badware: 11065-32, 2h.29m Δ
  ublock-privacy: 3583-3, 2h.29m Δ
  ublock-unbreak: 2716-1, 2h.29m Δ
  ublock-quick-fixes: 399-0, 2h.29m Δ
  adguard-mobile: 11964-66, 2d.8h.55m
  easylist: 86924-530, 2h.29m Δ
  easyprivacy: 55156-776, 2h.29m Δ
  urlhaus-1: 26295-6, 7h.10m
  plowe-0: 3488-78, 19h.50m
filterset (user): [array of 5 redacted]
userSettings: [none]
hiddenSettings: [none]
supportStats:
 allReadyAfter: 2128 ms (selfie)
 maxAssetCacheWait: 255 ms
 cacheBackend: indexedDB

[u-RraaLL]

uBO isn't supported on mobile edge. MS add-ons team added it on their own.

Does the issue exist with uBO Lite?

[gorhill]

Other extensions function normally in Preview tab.

Other content blockers?

[Saksham-9]

Other extensions function normally in Preview tab.

Other content blockers?

I just tried out 3 new ad blockers, but they all didn't work on the preview page.

[gorhill]

So the issue is with the browser, not the content blockers. Some views exclude extensions, fir example the sidebar view in Edge desktop. Probably a similar restriction in Edge mobile.

[freezer2022]

Which means that it might turn out to be a duplicate of / or similar to:

• uBlock Origin does not filter 'Search with Google' sidebar results in Chrome #2524