In order to better answer your question, I will need to know what version of the software you are using? Download or are you directly signed into your online account?
In testing this issue, I had no problems changing that part in the Marital Status section of the return, while ensuring I removed the dates as well from previous entries.
You can do one of two things; but first, I will ask you to follow directives below to assist you in clearing your browser cache to help your browser connection with the software. Sometimes we forget to do this and it piles up and makes online live processes more difficult.
How do I clear my cache (browsing history)?