Before blaming the mouse

Odd scrolling is often software. Work through these checks before concluding anything about hardware.

Check settings

• OS scroll direction (“natural” vs. classic) and scroll speed — a flipped direction looks exactly like constant reverse input.
• Per-app smooth-scrolling or momentum options in the browser.
• Utility software that remaps the wheel (gesture tools, drivers).

Isolate the cause

• Try another USB port or receiver, and a second browser.
• Test the same mouse on another machine; test another mouse on yours.
• If the pattern follows the mouse everywhere, that observation carries the most weight.

Useful evidence

For a support request or return, attach an exported JSON report (“Export report”) plus the mouse model, OS, and browser version. The event table shows exactly what the browser delivered — no interpretation added. To isolate one change at a time, use the Run A / Run B comparison.