Template hierarchy is broken on pagination

I’m building my custom wordpress theme and I’ve created category.php file. It works fine, but wordpress is using index.php template on pagination (e.g. clicking on https://sitename.com/nabludatel/?cat=9&paged=2 gets me to page generated by index.php – global $template variable is also “index.php” )

I’ve tried to recreate .htaccess and refreshing permainks options – that didn’t help.

The problem is driving me mad.

Thank you,

Sania