multi-regional domainsCTL or domain/dirs

[viasite]

Hello, I need help with a multi-domain, multi-language project.
Everything interlaced correctly with hreflang without problems.

- formerly 9 domains, 9 languages->
domain1spanish.com -> Spanish
domain2english.com -> English
domain3deuth.com -> German
domain4.com -> Catalan
domain5.com -> Japanese
etc ...


categories and articles:
domain1spanish.com/categoria/categorias -> Spanish
domain2english.com/cates/category -> English
domain3deuth.com/cates/category -> German
domain4.com/categor/categorie -> Catalan
...


In the past they indexed more or less well and positioned well, although it was difficult for some languages.

Just a few days before the March core update I made these changes and now I can't stand my head.

- currently 10 domains, 16 languages
All with hreflang and intertwined correctly with each other.

I have reduced domains little by little from the domains with fewer visits and shortened the structuring of the entire project

domain1spanish.com -> Spanish
domain1spanish.com/ca -> Catalan
domain1spanish.com/ja -> Japanese
domain2english.com -> English
domain3deuth.com -> German


categories and articles:
domain1spanish.com/categories -> Spanish
domain1spanish.com/ca/categorie -> Catalan
domain1spanish.com/ja/categorie -> Japanese
domain2english.com/category -> English
domain3deuth.com/category -> German



Do you think I should reduce it all to domain1.com?
With the test of reducing some domains to domain1.com I have observed that there are many links in the sitemaps and it takes longer to index.
Do you think I should go back to single multidomains and the old structure?

[not2easy]

Some people who have used a single domain and various language subdomains are saying that Google is not using their "hreflang" tags correctly and is increasing their bounce rates. See this current discussion: [webmasterworld.com...]

[Kendo]

I have a multi-language setup that works well. Everything is in the one folder on the server. For example:

index.php detects whether you arrived at:
ar.example.com
cn.example.com
en.example.com
etc, displays the appropriate includes for header (individual meta-tags), menu and main body. Each include only lists links for their own language/url so there can be no crossover. For example:

about_ar.php
about_cn.php
about_en.php

When search engines spider cn.example.com they only see pages for cn.example.com. Each aliased domain has its own sitemap.xml. Each alias is submitted to search engines as a unique website.

The benefit of setting it up like this is that only one domain needs to be registered and one SSL wildcard for the domain serves all 25 sites for https://**.example.com

The search engines are providing unique reports for each alias.

[doc_z]

Never change a running system... If the current system works, why should anything be changed?

By the way, the description does not sound like a multi-regional site, but like a multilingual site (such as Wikipedia). In contrast to multi-regional sites on a single domain, I have not yet observed any major problems with multilingual sites (on a single domain).