I prefer doing the SSL integration on the first day.
Because the backlinks you have created till now are pointed to Non SSL site so do a proper re-direct with 301. It might take time 1-3 months to get back in track but in the same time you can start building backlinks with https://

No, never had that experience because I'm smart enough to not mess with an already ranked page/URL.

You should 301 all the old pages to the https version of the same page, ranking should stabilize slightly below where it was, you lose >10% of your linkjuice as far as I know. However often that is enough to move you to the second page of something you were once on the first page for.

Don't worry about it, with in some time Google will replace the all pages with https:// and redirect your http to https using .htaccess file and also add your website with https in the webmaster account and submit the sitemap with https also to be get it indexed.

If you gather people's data, you need it. If not, you are blowing smoke.

You can't just "ssl" and forget it.

If it's not done right, you screw yourself.

-There are varying levels.
-Not all of them are compatible across browsers, mobile, etc.
-They slow your site down.
-You need the plain version left up for many, many reasons.
-They are not for the faint of heart...or plain jane websites.
-Big sites do it right the first time, as they have a gaggle of people at their disposal who do it right.
-Getting on board some fad is not prudent if one does not read ALL of what google actually proposes.
-Amateur webmasters who have no clue how the internet works, are first to muck things up....then come here.
-etc., etc., etc.

Paul

My website ranking improved after SSL installation.

Make it sure you've used a 301 redirect for all of your website links. It'll take some days to reindex your new links. Ping all of your website links and post on social media. Thanks :-)

Yes, the ranking drop is normal. You have many links pointing to the non-https version of your site, but any pointing to the https version.

That said, you have two options:

One is to download from Google and Bing the reports of your backlinks, and start asking every webmaster in the list to edit the link he gave you.

AND, two, you create new links.

Hope this helps.

The only think that you can do (or in your control) is to 301 redirect non-secure to secure protocol (https://) and to change the the preferred way to https:// in search console. Over the time Google will update your indexed pages from http:// to https:// and hopefully you will start seeing improvement in your rankings.

In order not to affect the Seo when installing SSL, you should definitely install 2 pugin is Really Simple-SSL and SSL is Insecure Content Fixer, the purpose of this plugin is to fix bugs and move towards the HTTPS protocol.