If your Slim EX Wireless Mouse (ST-MEXC, ST-MEXS) moves erratically, misses clicks, or stops scrolling, try these steps.

How to fix tracking and scrolling on the Slim EX

1. Use the mouse on a solid, non-reflective surface, since glass and glossy desks confuse the optical sensor.
2. Charge the mouse, since low power causes lag and missed clicks.
3. Wipe the sensor window on the underside with a dry, lint-free cloth.
4. If you use the USB-C receiver, move the receiver to a port closer to the mouse. If you use Bluetooth, remove the mouse from your Bluetooth list and pair the mouse again.
5. Press the DPI button to adjust pointer speed. DPI, or dots per inch, sets how far the cursor moves for each inch you move the mouse.
6. Test the mouse on another computer to confirm whether the issue is the mouse or your computer.