Fix a website bug -- 2

I have a specialist education recruitment website. educationrecruitment.expert. There is an error when a candidate registers, that if they have not filled in all the required fields, it appears as if nothing happens after they have clicked "Register", however the page should scroll back to the field where they missed filling in the required details and where they will also see the pop up warning "This field is required". It scrolls back the first time they click "Register" if they have missed some details, however after that if they go to the bottom of the page and click register again, it just stays there. If candidates fill in all details, there is no issue and the registration is successful. The freelancer who previously took on this project, has now taken off the text "Required field" from one of the required fields titled "Grade Level" whilst still leaving the field as a required field and has also removed the pop up warning "This field is required" from the above mentioned required field "Grade level" that should pop up next to the field that should have been filled in, and thus candidates no longer know that this field needs to be filled in, meaning now there is no way for a candidate trying to register on our website, to know why their information and thus registration was not successful. What is needed As per the original issue, I need the page to scroll back to where any missing details need to be filled in and either the field "Grade Level" made into a non-required field or the words "Required field" as well as the pop up warning "This field is required" to be reinstated. Please see attachment "Registration bug [login to view URL]" which includes screen shots.