Fix mouse button, double-click and scroll problems
Run the relevant online mouse test, write down the event pattern, then change one variable at a time. This keeps a browser quirk from looking like a hardware failure.
Check Windows or macOS settings and another browser
Open the same page in a second modern browser. If the symptom disappears, clear extensions and compare double-click speed, pointer acceleration and accessibility settings before replacing the mouse.
Swap the USB port or wireless connection
Wired mice should be tested on a direct USB port. Wireless mice should be re-paired with a charged battery and receiver close to the mouse. Compare Bluetooth with a 2.4 GHz receiver when available.
Clean the sensor and wheel
Dust can cause sensor skips or an encoder to jump. Clean the lens and wheel opening carefully, then repeat slow and fast scroll tests on the same surface.
Test on another computer
A second computer is the fastest way to separate a switch issue from an OS setting. Keep the same surface and test order.
When to consider an RMA
Consistent missing clicks, repeated sub-50 ms intervals or hold-drop events across browsers and computers are strong evidence to share with the seller or manufacturer.