Run the check
Scroll one notch upward at a time and record missing or opposite-direction events. Repeat downward separately.
Try the same wheel on a page that can actually scroll, then compare its visible movement with the event log.
Change only the connection or wheel mode and repeat the same notch sequence before testing another computer.
Read the result
Intermittent opposite-direction events differ from a consistent reversed scroll setting. No events in any app differs from a page that has no room to scroll. A repeatable one-direction fault needs device comparison.
Limits and next step
A browser receives wheel deltas after drivers and settings. It cannot inspect the wheel encoder or infer a failed part from one reversed event.
Repeat the check after changing one setting or connection. Keep a record of what changed before deciding whether the device needs service.