Get an error flash but then works

upgrade to wp 5.01, update all google recaptcha V3 keys, test form on wordpress sites. some sites give an error the first time to first few times then error msg stops. it’s a quick flash of “There was an error trying to send your message. Please try again later.” but immediately after that the form sends and i get a Sent msg. don’t know if it’s a cache problem or Contact Form 7 issue.
Contact Form 7 error