Have you attempted to make the changes in another browser? If it works, then it's likely a caching issue on the other browser. I've noticed that happens a lot with the DNS Management system. It doesn't like caching for some reason.
If that doesn't work, please contact phone or chat support as it's likely a server-side issue.
I am a GoDaddy End User - Just Like You * Please note that I offer free advice on this forum. I DO NOT answer private messages. Please ask your question in the proper forum so the answer can assist EVERYONE in the community and not just you. Thanks! *
Once your issue is resolved, please be sure to come back and click accept for the solution