This is because some USB devices emit radio frequency that can interfere with wireless networking. If your wi-fi works but is frequently dropping, unable to connect, operates extremely slow, or is nearly useless, a possibility exists of hardware interference with certain USB 3 or USB-C devices and the Mac. Disconnect USB 3 / USB-C Devices, Docks, Hubs, etc from the Mac If you do not have any system software updates available, go ahead and restart the Mac anyway, as sometimes a simple reboot remedies wi-fi and network issues. Be sure to backup your Mac before installing any system software update. You can check for and install system software updates in macOS by going to the Software Update control panel in “System Preferences”. It’s always a good idea to keep system software up to date, and thus your first step should be to check for any available system software updates and install them if applicable.

Install Available Software Updates, & Reboot the Mac Backing up a Mac with Time Machine is easy, don’t skip it. A full system backup is essential so that you can restore from if something goes haywire, and to prevent data loss. This is essential because some of the troubleshooting steps involves accessing and removing system level configuration files.

Important: Back up the Mac before going any further. Some of these are fairly simple, while others are more complex and require setting up new network profile information, moving system files, using custom network configurations, and other techniques that typically resolve wireless. We’ll walk through a variety of steps to troubleshoot wireless networking issues on the Mac. Troubleshooting Wi-Fi Problems with MacOS Mojave This troubleshooting guide will aim to troubleshoot and resolve wi-fi problems and issues with MacOS Mojave.

Messages on mac not working 10.14.2