[Bug]: UI Overlapping and Multi-Window Synchronization Issues

[itsjustwhitee]

Description

First of all, thank you for the amazing work on Zen Browser! The progress over the last few weeks has been impressive. However, I’ve encountered a few persistent issues when using multiple windows within the same space that affect both the UI and the general stability of extensions.
This browser has great potential, so, devs, keep going!

1. Multi-Window Synchronization & Tab Loading

When running 2+ Zen windows simultaneously in the same space:

• Sync Lag: when opening the browser (such as after boot) tabs sometimes fail to sync their state or do not load (empty page, and often empty title and favicon). Even if the url is correct, they do not load (nor with force reload), the only solution I found is to close and re-open them (tabs).
• Loading Issues: If a tab has been inactive for a while or was opened in a different instance, it occasionally fails to load entirely when switched back to or loaded in another window.

2. Extension Instability

There seems to be a conflict when multiple instances/windows are active. The extension menu (such as Bitwarden or DarkReader) often fails to trigger or stays stuck on a loading animation. It appears as though the different windows are competing for the extension process, causing the UI of the extension to become unresponsive. This, IMO, has a similar behavior as pages on the last point of section 1.

3. UI Layout & Overlapping Issues

I have noticed several graphical regressions regarding the sidebar and header:

• Sidebar Collision: The side and top sidebars occasionally overlap or become "stuck" when toggled (compact mode), tipically the side one stays "open".
• Responsive Scaling: When the window is not maximized (specifically when resized horizontally), internal elements of the Zen interface overlap, making some controls unreachable. Visual reference follows.

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Environment

• OS: Windows 11
• Zen Version: 1.18.10b (64-bit)

Note that I had the same issues among different pc with same OS (always updated to last versions).

My setup (Settings and Mods)

Here some pictures of my settings and mods follow.

Steps to Reproduce

Open 2+ more Zen windows in the same workspace and a few tabs.

• Sync and Extension Issues

  1. Close every instance of Zen (or reboot).
  2. Reopen Zen.
  3. Check if tabs/extensions loads correctly.

• UI Overlap

  1. Resize one window to a non-fullscreen horizontal width.
  2. Check corners.

• Sidebars overlapping: Not sure about how to reproduce.

Expected Behavior

• Extensions should be responsive across all open windows/instances.
• The UI should adapt fluidly to horizontal resizing without overlapping elements (eventually with a compactation and an expansion menu).
• Tab states should remain consistent across instances (always, except for containers) and sessions (if enabled).

If anything else is needed, make me know, I will provide ASAP!

[baraapro]

+1 for this on my Windows 11. Tabs are not loading when opening new windows. instead it shows "New Tab".

[mr-cheffy]

What version are you on?

[itsjustwhitee]

I am on 1.19.3b and I have also noticed that bug

[baraapro]

What version are you on?

1.19.3b

[mturley]

I'm seeing the same behavior on Mac OS, running 1.19.8b. Everything works great when I have one window, but sometimes when I have multiple windows, tabs will fail to load in the same way as described. In particular, this usually happens when I'm in window A and I open a background tab (Cmd+click) and then try to switch to that tab in window B. in window B the tab doesn't load, but in window A if I switch to it it loads.