Upgraded to Sierra and trackpad won't work with wifi

[dorothyv]

I have a mid-2012 MacBook Pro. I upgraded to Sierra 10.12.6 a couple of weeks ago. Since then, whenever I try to use the trackpad while connected to wi-fi, the trackpad is impossible to control - jumps all over the place, backspaces over text I'm trying to type, opens random applications. As soon as I disconnect wi-fi, it's much better, though still with a delayed response time and imprecise movements. (I haven't tried to test the trackpad using Ethernet yet).

Which is more likely?

1. A hacker takes over my MacBook when I connect to wi-fi
2. The Sierra installation caused the problem
3. My trackpad just coincidentally gave out

Thanks!

 

[Audit13]

Have up dated to the final High Sierra release? Maybe your Macbook needs a fresh install of High Sierra?

 

[HDFan]

Here's an article about WiFi/Bluetooth interference:

http://www.goldtouch.com/stop-bluetooth-interference-messing-devices/

Not my area of expertise, but I'd try changing WiFi channels, or disabling the 2.4 GHz channel and just try 5 GHz if you can.