Steps to reproduce the issue

In the "native" com_component one finds two series of files in the directory
\components\com_content\views\category\tmpl
default.php and its dependents --> is executed for a articlelist
blog.php and its dependents. -> is executed for a blogcategory

In the override I installed one series of files :
template/html/com_content/blogPieter.php and five other files (including the xml file)

Then I am able to select the blogPieter in a menu item I did create.

BUT,
when I do execute that menu item, the article list layout is executed
thus the
\components\com_content\views\category\tmpl\default.php

instead of my blogPieter from the override.

Expected result

Execution of my blogPieter

Actual result

Execution of the article list (default.php)

System information (as much as possible)

Bug is not present in joomla 3.8.2 on windows, but it is present on linux with joomla 3.8.2

Additional comments

when I change /html/com_content/blogPieter.php (and the other files) to
template/html/com_content/blog.php

and I change my menu item to categoryblog, I do get the overriden version of the blog.php.
(blogPieter may then of course be removed)

Thus the BUG is, on linux :

1. I can select in the administrator environment the new layout from the override in the template

2. It is NOT executed, it is the default.php, thus the articlelist that is executed instead.
   as can be seen in
   http://www.fotografiepieter.be/portfolio/test-telt-niet-wej

3. If I do a direct override of blog.php (and the other four files) I do get that adapted version for blogcategory, as can be seen in http://www.fotografiepieter.be/blog