Hi there,
We request you to allow us to help you out before jumping in to provide a one-star rating with three back to back comment. If we are unable to help you out and ignore your support request then your one-star rating would have been justified.
You can contact us directly from here https://wpeverest.com/contact/ or post a query here https://wpeverest.com/support-forum/forum/user-registration/
We have responded almost every forum topics created and tried our best to help our users.
If your user is not able to login even with correct password then your user should get some error message. Let us know what that message is and we will try to debug that.
We checked the issues that you have pointed and everything seems to be working fine on our test site including shortcode, registration, and login. We need more information so that we can help you out on this. Please contact via above links for detail support.
We hope you can review the rating once your issue has been solved.
Have a nice day!.
Thanks.
WPEverest