getting 404 page not found?

Hi there,
I have had the plugin a little while now and still, have 3 months of support left so I think its time to ask a question since I can’t get it fully working.
I have same the shortcode [dwqa-list-questions] to a page named FAQ and set it also in the settings as the page to view. I have updated and saved all permalinks. 
I can view the page as a preview but when saved and viewed I get a 404 error.
Help really needed on this one, please.