HTTP HTTPS Migration Gone Wrong - Please Help!

[GWMSEO]

We have a large (25,000 Products) ecommerce website, and we did an HTTP=>HTTPS migration on 3/14/17, and our rankings went in the tank, but they are slowly coming back. We initially lost 80% of our organic traffic. We are currently down about 50%.

Here are some of the issues. In retrospect, we may have been too aggressive in the move.

1. We didn't post our old sitemaps on the new site until about 5 days into the move.
2. We created a new HTTPS property in search console.
3. Our redirects were 302, not 301
4. We also had some other redirect issues
5. We changed our URL taxonomy from http://www.oursite.com/category-name.html to https://www.oursite.com/category-name (removed the .html)
6. We changed our filters plugin. Proper canonicals were used, but the filters can generate N! canonical pages. I added some parameters (and posted to Search Console) and noindex for pages with multiple filter choices to cut down on our crawl budget yesterday.

Here are some observations:

1. Google is crawling like crazy. Since the move, 120,000+ pages per day. These are clearly the filtered pages, but they do have canonicals.
2. Our old sitemaps got error messages "Roboted Out". When we test URLs in Google's robots.txt tester, they test fine. Very Odd.
3. At this point, in search console
   a. HTTPS Property has 23,000 pages indexed
   b. HTTP Property has 7800 pages indexed
   c. The crawl of our old category sitemap (852 categories) is still pending, and it was posted and submitted on Friday 3/17
4. Our average daily organic traffic in search console before the move was +/-5,800 clicks. The most recent Search Console had HTTP: 645 Clicks    HTTPS: 2000 clicks.
5. Our rank tracker shows a massive drop over 2 days, bottoming out, and  then some recovery over the next 3 days.
6. HTTP site is showing 500,000 backlinks. HTTPS is showing 23,000 backilinks.

I am planning on resubmitting the old sitemaps today in an attempt to remap our redirects to 301s.

Is this typical? Any ideas?

[STP_SEO]

our dev team has requested to 302 initially and then 301 as the final solution. Could this cause a problem for the temporary 302?

[muzzmoz]

Looks like you've done a sterling job GWMSEO. Well done!

I deal with a lot of small sites where the decision to move from http to https was made for them... by Shopify (many without them even realising). Some of these sites take months to recover. So, to see recovery within a few weeks is a good result.

Once question I have for you: how have you resolved the backlinks issue (your observation #6)?

What I have observed is that ahrefs doesn't associate the old (http) backlinks with the new version (https). I believe this then impacts backlink profile and subsequently MOZ Domain Authority, which then impacts rankings and traffic.

301 redirects ensure you don't lost the traffic, but it doesn't move the backlinks from http to https.

Nobody has been able to confirm or deny my suspicions yet. So:

1. Do you (or anyone in the MOZ community) know if these lost backlinks DOES impact Domain Authority?
2. Is there any way to fix it, other than go through all the old backlinks and manually change to https?

Murray

[GWMSEO]

Thanks to all for the help. Our rankings are climbing back. We should be back to status quo in +/-2-3 weeks after the move.

[brettmandoes]

Nice, good job! I would double check with your CDN provider to make sure implementation was done correctly according to their process. Unless you're saying you discontinued use of the CDN when you switched?

I wouldn't panic, just make sure your team knows that you can't control the rate at which Google re-indexes the website and that it's still early in the process to tell if there is an issue somewhere. Let Google do their thing and then once your traffic and rankings seem more regular, reevaluate. At that point I would add HTTP/2 support if possible and measure the impact from that because that provides some additional benefits such as a boost to site speed.

[GWMSEO]

Thanks for the punch list. Our rankings turned around some when we submitted the old http sitemap.

1. Images only on HTTP in CDN. HTTPS, No CDN.
2. Yes
3. Yes. (I was a stickler on this one)
4. Yes
5. Yes, Yes, Yes.
6. Yes
7. Yes, we fixed that.
8. Yes. Initially our https redirects were 302 (Not on me, LOL.). We resubmitted our old (http) sitemap file today to crawl so that Google can pick up the change.
9. Yes
10. Yes
11. No disavow file. Our backlink profile is remarkably squeaky clean. TF-57, CF-47

Bonus: Yes.

[brettmandoes]

1. Are you using a CDN?
2. Did you update all your internal links to https? 
3. Did you update all of your canonical tags?
4. Did you update all of your hreflang tags?
5. Are you using plugins/modules from a third party? Are they secure? Do they have documentation or a rep you can contact about migrating to https?
6. Some CMS's have specific settings that need to be altered when migrating - make sure those were done correctly. 
7. Use screaming frog to check for any external scripts, and ensure they're calling https. 
8. Did you update your old redirects?
9. Did you update your robots.txt file to include the new https sitemap?
10. Did you enable HSTS?
11. Do you have a disavow file? Did you update it for HTTPS?

Bonus:
Did you update all of your other paid campaigns, analytics, etc. to reflect the migration?

[tustind]

OK, that makes a big difference. Before you resubmit any sitemaps, make sure your technical implementation is perfect. Fix all sitemaps, make sure all URLs are properly 301'd, and make sure you are not generating any type of mixed-content security errors. Make sure all sitemaps are going to the new URLs. Most important, when a user clicks on an old URL (e.g., from search results or an old backlink), they need to be 301 redirected to the same page on HTTPS (not the home page). Then resubmit your sitemaps.

Your transition is still very 'young,' and it will likely take 6-8 weeks before Google completely replaces the old site with the new site in it's algorithms and search results. You should expect a temporary drop in traffic during this transition, but assuming you have done everything correctly, things should normalize after that.

[GWMSEO]

Tustind:

Sorry - we did it a week ago - 3/14/17.

We just changed the 302s to 301s yesterday. I believe we need to resubmit our old sitemaps for google to index the 301s.

[tustind]

So you made this migration over a year ago now? From my knowledge and experience doing a domain change, which has a lot in common with a https change, we experienced about 2 months of depressed traffic, after which point our traffic normalized and then continued on a growth trajectory. So I suspect that your biggest problem was not properly implementing the 301 redirects. You basically told Google that you were only making a temporary change, which could explain why after an entire year your site has still not been fully picked up. When did you change the 302s to 301s?