Password field in login acting odd

When i start up my computer and the login prompt appears, i start typing my password, and after about 1-2 seconds, whatever i had typed thus far is highlighted, as if i had selected the text with my mouse. then, if i type another ky, the text is replaced with the key i typed, just as if i had selected the text with my mouse. this has been happening since the first startup of my laptop(it is new). no other text field does this.
Windows 10, HP pavillion 15-cc1xx