Welcome to the site !!
Unfortunately , the issue is because you washed the bike and got the switch wet ....... The kill switch gets moisture inside it , if you try to start the bike with the moisture in it , it will usually fry the switch .... I am hoping that eventually Honda goes back to the old style kill button , as this new electronic one is not sealed tight enough to allow it getting wet .....
You might end up having to replace the switch ,,, then the next time you wash it , do what I do with my 2020 450R , put a gallon size ziploc bag over the bar end covering the switch and secure it in place with a garbage bag tie , then wash your bike , then remove the bag ..... This is a common issue with the new gen bikes , and I wish Honda would come up with a better switch design , as this happens way too often ....
