Claude.ai chat history not appearing in sidebar (works in other browsers)

[Cellulose-Type-C]

Preliminary Checks

• I have read and understood the important section above.
• I have searched existing issues and avoided creating duplicates.
• I am not filing an enhancement request.
• I have checked that this issue cannot be reproduced on Mozilla Firefox.
• I have checked that this issue can be reproduced once I removed all my Mods and Custom CSS.

What happened?

Claude.ai chat history does not load in the sidebar on Zen. Chats initiated in Zen are saved to Anthropic's servers (they appear correctly in Vivaldi and on mobile), but the sidebar in Zen shows no history — neither current session chats nor older ones. The user remains logged in between sessions; this is purely a sidebar/history fetch issue.

Expected behavior

sidebar loads saved chats from server as it does in Vivaldi/mobile Actual: sidebar is empty despite chats existing server-side

Actual behavior

Claude.ai chat history does not load in the sidebar on Zen. Chats initiated in Zen are saved to Anthropic's servers (they appear correctly in Vivaldi and on mobile), but the sidebar in Zen shows no history — neither current session chats nor older ones. The user remains logged in between sessions; this is purely a sidebar/history fetch issue.

Steps to reproduce

Steps to reproduce:

1. Log into claude.ai on Zen
2. Start a conversation
3. Close and reopen Zen
4. Sidebar shows no chat history

Screenshots and videos

No response

Version

1.19.3b

What platform are you seeing the problem on?

Other

What component is this issue related to?

Customizable UI / Toolbars

Relevant log output if applicable

Network tab shows no failed requests to claude.ai during the session. Intercom websocket (unrelated) shows as blocked. No cookie clearing on close, privacy.firstparty.isolate is false.

[mr-cheffy]

Does it work on firefox as well?

[Cellulose-Type-C]

Does it work on firefox as well?

Nah, it works on that one. I used Firefox both on Linux(Arch) and mobile(android). It works fine. Error is specific to Zen, i suppose. Also recently I experienced a new kind of bug where my current chat seems vanished in middle, not in sidebar, apparantly inside chat window. And this is specific to Zen too.