Does your Mac’s pointer mysteriously disappear? It could be Universal Control

Universal Control extends your mouse, trackpad, trackball, keyboard, and other input devices across multiple Macs and iPads signed in to the same iCloud account. Put your devices together and you can move seamlessly from one screen to another with the mouse and use your Mac to manage inputs on an iPad or another Mac.

But you can find yourself in a confusing scenario if you forget that Universal Control is enabled and your devices are not so close to each other. Recently, both me and a colleague had the same mystery: our cursor kept leaving our screen. What strange journey was it on? It turned out that it had visited another Mac that we had active in a different part of the house.

This situation occurs only occasionally because several conditions must be met:

• Both Macs are unlocked and running.
• They are within a few meters of each other.
• Universal Control’s “Push through the edge of a screen to connect a nearby Mac or iPad” is enabled (see below).

In both my and my friend’s case, our Macs tens A few feet apart—mine was a whole floor away—but Universal Control still considered them close enough. And we both also typically have our Macs turn their lock screens on or sleep when not in use for a reasonable period of time. We happened to come across a window with the two Macs unlocked and decided they were close enough to trade inputs.

You can prevent this scenario from happening if it affects you by choosing  > Sleep or  > Lock screen of the Mac you don’t want to use.

You can also disable the setting in System Preferences † Displays in Universal Control mentioned above, “Push by…” and the one below it, “Automatically reconnect to a nearby Mac or iPad”, to prevent automatic connections. Then, to connect to a nearby Mac (or iPad), click Add screen in the Displays preference pane and choose the other device under the Pairing keyboard and mouse section.

This Mac 911 article answers a question from Macworld reader Jeff.

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