Custom Taxonomy archive pagination doesn't work (404 error)

I was trying to find the reason why this is happening and finally found the issue, but I don’t know how to solve it.

USAGE:
I registered in my WP a custom Custom Post Type and a Taxonomy (“professions”). All is working fine and I managed to create a “taxonomy.php” derivative copy of this file (in fact I did a copy of the “taxonomy-portfolio-category.php” as an image to work on, in order to be called by WP correctly. So I created a “taxonomy-professions.php” file.]

All is fine and working, but the pagination process.

At first I tought that it was a problem with the pagination/whatever, so I installed a pagination plugin and the problem is still the same. In the first page of all taxonomies, all is fine, even with the pagination calculation numbers:

But when you click on Page 2, a 404 error shows up (page not found).

I tought that the problem was realted with my permalinks, so I deactivated them, so the structure in my tests are:
https://www.mywebsite.com/?professions=management-occupations

And the access url to the second page is:
https://www.mywebsite.com/?professions=management-occupations&paged=2

And still this way, a 404 error is showing up…

Banging my head all the way during hours I found the cause: for some reason, the “Page 2” page loading is calling a WP query with the post_type called “portfolio-category”.

Please see a dump of “query_vars” of the first page, correctly called with my custom taxonomy data.
PAGE 1 Dump:

PAGE 2 Dump (404 Error):

How can I solve this?

Thanks!
;)