My changes won't save

I manage to change one section and now when I try to change and save anything else they won't save.

I have checked your forms and they are saving on my end, what I would suggest you is to make sure your session has not expired, sometimes the session has already expired and this ends in changes not saving, the save button gets stuck on saving but never ends. 

I will also suggest you to check the revision history of your form so you can see which changes were applied or not: How-to-view-form-revision-history

If this persists, try opening your form in a different web browser or computer, testing from a different networks will also help to know if this is a networks problem. 

In case that you're unable to save changes even testing as suggested above, please share us a screenshot of the web console, these keyboard shortcuts will help you to get it: 

Google Chrome:

Mac: Command + Option + J

Windows: Control + Shift + J

Firefox:

Windows: Ctrl+Shift+K

Mac: Command+Option+K

This guide will help you to upload the screenshot on your next reply: How-to-add-screenshots-images-to-questions-in-support-forum

We'll wait for your response. 

I believe the issue was it was a duplicate form.  I deleted the duplicated and started another form and have had no problems since.

I like the 4.0 but I could not see how to pull my old forms over.  Is it possible?

You can switch between using the v3 and beta v4 builder from your account settings page:

https://www.jotform.com/myaccount/settings