The Network Hop
macOS is built for seamless mobility. If you use a MacBook in an environment with multiple available Wi-Fi networks (like a corporate office with “Guest” and “Internal” networks, or a home with both a 2.4GHz and 5GHz router), macOS constantly scans the airwaves to determine which network has the strongest signal. If the network you are currently connected to drops in signal strength, macOS may automatically disconnect you and switch to another known network with a better signal. While this keeps you online, it is catastrophic if you are in the middle of transferring files to a local server or hosting a video call, as the network hop briefly interrupts all your traffic.
Disabling Automatic Network Joining
To ensure absolute connection stability and stop macOS from automatically switching Wi-Fi networks in the background, you must disable the auto-join feature for all networks except your primary one.
Click the Apple logo in the top-left corner and select System Settings. In the left-hand navigation pane, click on Wi-Fi. In the main window, you will see your current network at the top, and a list of “Known Networks” below it. Scroll down to the very bottom and click the Advanced… button. You will see a list of every Wi-Fi network your Mac has ever connected to. For every network on this list that you do not want your Mac to connect to automatically (e.g., the 2.4GHz band, the Guest network), click the three horizontal dots (…) next to the network name and uncheck Auto-Join. Ensure that only your preferred, primary network has Auto-Join enabled. Your Mac will now cling to that single primary network until the signal completely dies, refusing to hop to alternative networks.