Seems to be rather randomly and on users with slower connections on windows OS. We tried lots of times for tests with Recaptcha invisible on mac and did not get any problem registering.
The form is rather standard see
activ-ha.com/inscription
( I removed the step by step also due to google pbs)
I remember that we had this issue a couple of years ago and had to switch to internal but cannot remember what was the cause. Maybe that was some auto actions but not sure.
PS: the output of the users getting the problem was a page with url /profil/saveregisters with a js alert saying that the session had expired or the cookies were not activated on the browsers. Same thing with firefox, edge or chrome. Switching to internal spam mode solved it
PS2 : with a re try I get
Code:
Content Security Policy: Ignoring “http:” within script-src: ‘strict-dynamic’ specified
XHRPOSThttps://www.google.com/recaptcha/api2/reload?k=xxxxxxxx
[HTTP/2 200 OK 136ms]
Content Security Policy: Ignoring “'unsafe-inline'” within script-src: ‘strict-dynamic’ specified
Content Security Policy: Ignoring “https:” within script-src: ‘strict-dynamic’ specified