Wifi Problems when Notebook not connected to power source I have a Macbook Pro 2016 that is connected to 2 external monitors via Thunerbolt. When my Macbook is not connected to power supply, I can connect to the wifi with good signal strength but loading websites (or sending a ping) takes forever.

But when I plug in the power supply, the websites suddenly load instantly. 

The problem does not occur when my 2 external monitors aren't connected.

Any ideas why this problem occurs?
First thing is to reset the SMC. Shutdown your Mac, the press &amp; hold ShiftCtrlOptionPower for 10 seconds, then boot normally. 

When you see a behavior change due to changes in power supply (plugging in a MacBook for example), chances are it's an SMC issue.

You can get more info by reviewing Resetting Your SMC