Remoting to a Windows 10 computer with dual monitors that shows a second trailing mouse on one screen. Mouse trails are NOT turned on. This is more like a duplicate that lags behind the main pointer. Only affects one screen.
Please double-check if you have the Rendering of hosts cursor set to Always in the Connection Properties window -> Cursor tab. If this is the case, please try switching it to View only mode active or Never and see if this helps to resolve the issue.
In this case, please also try enabling the Use legacy capture mode feature in the Host Settings window -> Other tab and see if this helps to resolve the issue. Please make sure to restart Host after enabling the feature in order for the changes to be applied. You can also enable the feature via the Remote Settings feature - in this case Host will be restarted automatically after you submit the changes.