control-panel / mouse-properties /
on the buttons tab … which is the current button-configuration? i use old-style mechanical mouse so i have mine set on "other pointing device" rather than laptop's touch-pad. furthermore, on the device-settings tab, the touchpad
(oem) is disabled.
have attached couple screen-caps if they prove valuable.
you might also try, on the device-settings tab, placing checkmark in the
"disable internal pointing device when external usb pointing-device is attached" field. then i'd reboot.