This just started to happen. I have a 2018 MacBook Air and use a Dell monitor for a second screen. Every time I disconnect the monitor from my laptop, the trackpad doesn’t function properly. The cursor moves, but you cannot select anything. The only way I can fix it is by rebooting. Obviously this is hugely inconvenient :( Can someone please help!
Hi Hkeycon8,
Does this issue persist in safe mode. This will help determine if one of your startup items is causing the issue. You can learn how to do that here: Start up your Mac in safe mode - Apple Support
Additionally you can narrow things down by testing this issue in a different user account. That will determine if the issue is happening just with your account or across the entire operating system. You can learn how to do that here: Add a user or group on Mac - Apple Support
If this doesn't help you can reach out for additional support here: Get Support
Take care.
Trackpad unresponsive after unplugging external monitor
