In the Address field, please type-in your address to see if it will auto-populate with different addresses. You should be able to choose your address from there, and when you click on it, the rest of the fields should auto-populate.
Let me know if this doesn't resolve your issue.
I checked this for you and I was not able to replicate the issue you are experiencing. Please, try clearing your cache and cookies and using a different browser to check if you are able to click on the field above the street field which is greyed, click the one with text ''Start typing your address'' and you will be able to update your address information.
Let us know if you need further help.