Newsletter block title and description suddenly gone?!

I'm noting that title and description are suddenly gone for the newsletter block.... i was trying some changes in the Styles section, not sure what went wrong here.,,,   

Hi. Can you share site url? We can take a look

https://avocado-bagpipe-e9kf.squarespace.com/  

password 123 

1 hour ago, 23802y08292 said:

https://avocado-bagpipe-e9kf.squarespace.com/  

password 123 

In Custom CSS, find this code

header {
    position: fixed !important;
    width: 100% !important;
    z-index: 999;
}

change it to

header.Header {
    position: fixed !important;
    width: 100% !important;
    z-index: 999;
}