Broken page templates for child pages

Hello,

Just would do following:
Example Parent -> Example Children
with anothers page templates for parent and it’s children.

Page template works fine for Example Children if parent is not set. However when I set parent for it, page template doesn’t work. Moreover, Example Children is loaded on single.php + content.php instead on page.php + content-page.php (as is by default for page).

Using WordPress 4.2.2 and theme builded on Twenty Fourteen (on main files, not child theme, however I didn’t touched any related to pages or even templates).

Hope for help and thanks in advance!
Greetings