Mouse cursor lags with external monitor

I get the mouse lag no matter the mouse used, be it a usb mouse, or the touchpad of the laptop (Macbook Pro 2016 with touchbar). It can be seen clearly by dragging the mouse on the external monitor and then dragging the mouse on the laptop screen (the mouse cursor moves in a much sharper way on the laptop screen).

This is on a Macbook 13,2, on mac OS 10.12.6, with a Dell P2415Q and HDMI cables (either a direct HDMI to USB-C cable or with an adapter for USB-C to HDMI and a straight HDMI-HDMI cable). Laptop has only USB-C ports, so I don't see how trying a different cable would help.

Reported this bug with a link to this thread to apple, they probably won't do anything about it.

Yeah... amazing. I do bought think for 2300 EUR and mouse chopping quite a lot, where on ALL another system no problems as far. It's awesome, that there is such easy solution... wait a minute... the new MBP don't have any port on second side... it's even do not have nothing that 2 USB-C like (whatever Apple call it) ports...

I'm quite angry...

My magic mouse 2 have been having issue on high sierra with external display. My macbook lit is closed.

Out of all the ways suggested.

Indeed changing the USB port to the other side works but if you wish to continue using the USB port.

Another way is to change to a better HDMI cable which works for me.

Same problem with an 26“ Ijyama monitor connected via HDMI to a 2014 15“ Retina MacBook Pro with Intel HD Graphics. Sometimes this setup works for several hours until the cursor suddenly starts freezing and jumping on external mouse and integrated trackpad. Additionally, the external screen turns black for a couple of seconds repeatedly. Unplugging the monitor solves this issue immediately, but plugging it back in will result in the MBP not recognizing the monitor anymore. A reboot does not help, and Windows via BootCamp does not recognize the display either. Same issue with other HDMI cables and other monitors. Only thing that helps is waiting til next day and waking the MBP while the monitor is plugged in. Then the setup will most likely work for 3-5 hours.

Wrapping the display cable in tinfoil fixes this issue.

With all of the tech, this just blows my mind. Tin foil. It actually makes sense - however this means if you had a USB cabled mouse, it would work perfectly right?

Absolutely same problem... Dell mouse... it's working on EVERY different device, BUT MBP.
<irony>Well, I'm so lucky, that MBP is so cheap... </irony>

I can confirm that this was exactly the cause of the issue when i was experiencing it. Moving the dongle from the HDMI side to the opposite side fixed it instantly.

Just to note i was using an usb hub beside the HDMI port. Which was interfering with my magic mouse 2.

Another way i found working was to wrap tinfoil around the connectors. it works well.

Confirm from my side as well. Moving infra-red receiver for my wireless mouse to another side of Mac from HDMI cable solve the mouse freezing!

I had this same problem on my macbook pro 2017 w/ touch bar and was able to solve it simple by connecting to usb-c ports on the other side of the laptop... weird.

Incredible, 5 years later, brand new Macbook, same issue, same solution.

Thanks, Kraasa

I had the lag too; When I moved the hdmi hub away from the power outlet and away from any other adapter, lag has stopped