Can’t Save Drafts or Preview page

When I create a new page or post and start typing then Click Save Draft the page looks like it is saving but it reopens the page with no content in it.

If I go to All Pages or All Posts the page or post is there but in saved as a draft. Opening it all the written content is still there.

If I want to preview the page it does the same and opens a new post or page.

Why is it doing this?

thanks

Colin

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