[iOS 26] “Close All Tabs” action is executed with delay

[data-sync-user]

Steps to reproduce:

1. Open Firefox on iOS 26.
2. Open multiple tabs in normal browsing mode.
3. This can be achieved by using the debug option the settings (press the version 5 times, and toggle “Open 50 “Mozilla.org“ tabs“ multiple times.
4. You need at least an infinite amount of tabs (above 99 tabs) to get the issue from this ticket.
5. Tap the Tab Tray button.
6. Select to Close all tabs.

Expected result:
All tabs should be closed immediately after selecting Close All Tabs.

Actual result:
The action is performed with a noticeable delay before the tabs are closed.

Device & Build Information:

• Device: iPhone 16 Pro (iOS 26 beta 8 – 23A5330a)
• Build version: v9000 (60549)

ℹ️ Reference Person

+@Foxbolts+

┆Issue is synchronized with this Jira Bug

[Aniket-pd]

Hi,I can work on this issue

[lmarceau]

FYI I think this relates to the work done in #28250 (that wasn't merged since it was needing some more tests). I'll assign this issue to you @Aniket-pd, let us know if there's anything!

[Cramsden]

Hi @Aniket-pd and @lmarceau I didn't realize this issue was marked for contributor okay and was assigned to me. I am sorry! I have also opened a PR for this work! Let me know your thoughts...

[Aniket-pd]

No problem @Cramsden! ,I’ve already been working on this in #29974 ,maybe we can compare notes and align on the best approach?