How to Fix macOS Focus Problem with Multiple Window Apps on Third Displays

• The article explains a bug in macOS that causes the focus to switch to a different display when clicking on a multi-window app on a third display.
• The article provides several ways to fix or avoid the bug, such as using single-window apps, using only one display for each app, using third-party apps, using keyboard shortcuts, or disabling automatic switching of spaces.

If you are using a Mac with two external monitors, you may have encountered a frustrating issue when switching between different apps on different displays. Sometimes, when you click on an app window on one display, it briefly gains focus and then immediately switches to another app window on another display. This can be very annoying and disrupt your workflow.

In this article, I will explain what causes this problem, how to reproduce it, and how to fix it. I will also answer some frequently asked questions related to this topic.

What Causes the Focus Problem?

The focus problem is caused by a bug in macOS that affects the way it handles multi-window apps on multiple displays. A multi-window app is an app that can have more than one window open at the same time, such as Chrome, Safari, Finder, or Terminal. A multiple display setup is when you connect one or more external monitors to your Mac, either through HDMI, Thunderbolt, or USB-C.

The bug occurs when you have two or more windows of the same multi-window app open on different displays, and you try to switch focus from another app on a third display. For example, let’s say you have Chrome open on display 1 and display 2, and Finder open on display 3. When you click on Finder on display 3, it briefly gains focus and then immediately switches to Chrome on display 2. This happens regardless of whether you use Mission Control, the Dock, or the keyboard shortcut to switch apps.

The reason for this behavior is that macOS treats each display as a separate space, and each space has its own active window. When you switch focus from one space to another, macOS tries to activate the last active window of the same app on the new space. However, if the last active window of the same app is on a different display, macOS gets confused and switches to that display instead of staying on the current one.

How to Reproduce the Focus Problem?

To reproduce the focus problem, you need to have a Mac with two or more external monitors connected, and a multi-window app with two or more windows open on different displays. You also need to have another app open on a third display. Here are the steps to reproduce the problem:

1. Open a multi-window app (such as Chrome) and create two or more windows.
2. Move one window of the app to display 1 and another window of the same app to display 2.
3. Open another app (such as Finder) and move it to display 3.
4. Click on Finder on display 3 to make it active.
5. Observe that Finder briefly gains focus and then immediately switches to Chrome on display 2.

You can also try rotating the displays or changing the arrangement of the displays in System Preferences > Displays > Arrangement. You will notice that the focus problem persists regardless of how you configure your displays.

How to Fix the Focus Problem?

There are several possible ways to fix the focus problem, depending on your preferences and needs. Here are some of them:

• Use a single-window app instead of a multi-window app. For example, instead of using Chrome with multiple windows, use Safari with tabs.
• Use only one display for each app. For example, instead of having Chrome windows on display 1 and display 2, have them all on display 1.
• Use a third-party app that manages window focus better than macOS. For example, Moom is an app that lets you easily move and resize windows across multiple displays, and also prevents the focus problem from happening.
• Use a keyboard shortcut to switch apps instead of clicking with the mouse. For example, press Command + Tab to switch between apps without changing displays.
• Disable automatic switching of spaces in System Preferences > Mission Control > Displays have separate Spaces. This will make all your displays share the same space, and prevent macOS from switching displays when switching apps. However, this will also disable some features such as full-screen mode and split view.

Frequently Asked Questions

Question: Is this a new bug in macOS?

Answer: No, this bug has been reported since at least macOS Sierra (10.12), and it still exists in macOS Big Sur (11). It seems that Apple has not fixed it yet.

Question: Does this bug affect all multi-window apps?

Answer: No, some multi-window apps do not trigger this bug, such as Microsoft Word or Excel. It seems that this bug only affects apps that use native macOS window management APIs.

Question: Does this bug affect all Mac models?

Answer: No, some Mac models do not support multiple displays at all, such as MacBook Air or MacBook Pro with integrated graphics. It seems that this bug only affects Macs that have discrete graphics cards or external GPUs.

Question: Is there any official solution from Apple?

Answer: No, Apple has not acknowledged or addressed this bug officially. However, some users have reported that contacting Apple Support and providing feedback may help escalate the issue.

Conclusion

The focus problem with multiple window apps on 3 displays is a frustrating bug that affects many Mac users who use multiple monitors. It can disrupt your productivity and workflow, and make you lose track of your windows. Fortunately, there are some ways to fix or avoid this problem, such as using single-window apps, using only one display for each app, using third-party apps, using keyboard shortcuts, or disabling automatic switching of spaces. Hopefully, Apple will fix this bug in a future update of macOS.

If you found this article helpful, please share it with your friends and colleagues who may also experience this problem. If you have any questions or comments, please leave them below. Thank you for reading!

Disclaimer: The content of this article is for informational purposes only and does not constitute professional advice. The author is not affiliated with Apple, Microsoft, or any of the apps mentioned in this article. The author is not responsible for any damages or losses that may result from following the instructions or suggestions in this article. The author does not guarantee the accuracy, completeness, or timeliness of the information in this article. The reader should always exercise caution and consult a qualified professional before making any decisions based on the information in this article.