got problem on this plugin

after i install this plugin , i used for a while then i change my API key on google recaptcha , retype new API google recaptcha on tis plugin , after that everything should be okay but problem comes out

instead of showing captcha for new google captcha API key , my website show that captcha state “ERROR for site owner: Invalid site key” ,

this problem still exist even you leave the plugin form page in blank or even you uninstall the plugin

how do i get rid of this annoying message and go through the new API google captcha like before ???

here is my url website that show up this problem https://thewellnesschecks.com/medical-and-health/fruits-vegetables/there-is-a-rainbow-is-it-useful-and-worth-trying/

The page I need help with: [log in to see the link]