Run the check
Mark a fixed physical travel distance and keep the same surface.
Change only in-game sensitivity, then compare turn distance.
Restore it and change only the mouse DPI preset if supported.
Read the result
The same turn distance can result from different combinations with different behavior.
Limits and next step
Browser CSS pixels are not a direct measurement of hardware DPI.
Repeat the check after changing one setting or connection. Keep a record of what changed before deciding whether the device needs service.