I changed my Magento 2 store locale to Russian using the etws/magento-language-ru_ru plugin and the site loading speed significantly increased. Chrome shows that the waiting time (TTFB) is 12-15 seconds at least.
I'm using Apache 2. It server other files in a timely manner. When I use English as the store locale it takes a few seconds to load the page.
How do I fix the problem?