Changed from www to non-www lost all rank. Will it return?

[ThereNYC]

My web site used https://www.domain.com for the past 18 months. We finally got to #3 position for our top keyword. We changed web servers and our wordpress admin section somehow got changed to https://domain.com. As you can imaging I'm not too happy. We do have 301 redirects installed. Yesterday I noticed that our site was not ranking anymore. In fact, all our pages and our site URLs at https://www.domain.com have been de-indexed. I assume because that no longer exists.

Using site: all the web pages under https://domain.com (which were identical to the old www) are now listed. All of them. However, none are showing in searches unless we search for the business name. They are not appearing under keyword searches.

I would assume that the 301s (which are installed property) would make the site keep it's rank, as the pages are all identical.

Will we ever get our rank back? Should we switch back to www? Or do the 301s just take time to hit? How long if that's the case?

[JohnSammon]

Any chance you would be willing to share the URL so I can run some diagnostics?

A few things to look at:

1. Insuring that 301 redirects are in place to redirect non www to www and http to https

2. Google Search Console for any 404's that have popped up since the move. You'll want to redirect those too

3. Submitting your XMl sitemap to both Google and Bing via Search Console and Bing Webmaster Tools

4. Making sure that you've updated your prefences in analytics to https in both property settings and view settings