Wordpress logs out all users a few seconds after logging in, and soon afterwards blocks the IP as a result of failed login attempts - of which, by the way, there were none.
in the activity tab I see additional AJAX requests from user’s IP on /wp-admin/admin.php, (added by plugins), and each of this requests is flagged by Login failed and Invalid user cookies cleared
I’m kindly asking for any hint,
I have tested almost all possible plugin settings, turned off plugins, nothing helps so far…