i end up every 2nd or 3rd time on you wp login (with chrome)
if a link is set on a site what is not https and links to
http://www. the browser will always try the not ssl version.
but in fact that does not explain your problem.
but the site search you made will possibly always show you this result as in fact both domains are existing.
(the content from the domain you searched have just moved)
if you look into the results (cached version) you might see that both searches are showing to the com.
that means google understood very well that es is now com.
and what you actually did was asking google for the pages from your es-domain and google showed you the results from the com because it is 301 permanently moved.
so on a regular search there is nothing from the es in google.
that you have löst traffic on that domain may have to do with a lot of changes in the algorythm.
also your mobile version is not conform with coalition for better ads rules as there is more than 1/3 used from an ad.
in the first visable part of a mobile page you should only use 300x100 ads and put the 300x250 later in the content.
to understand google is quite easy because Google actually reacts on user signals like bounce rate and returning visitors. sure you can do a lot wrong onpage but I think this is not really your problem here. you are not the only one that have lost in the past 2 years.
one of the major issues is the mobile first index.
if your site have issues in mobile it will lose visibility in google.