Why is head cleared (vue & nuxt.js & element-ui)?

Question

Vue.js

I create a clean project on nuxtjs + element-ui
Add for example datapicker (the same with other components)
When the page is loaded, everything is fine, but after calling (clicking on the field) datapicker, the head (external css and title) is erased. Only js remains. It seems that element-ui completely replaces head, forgetting to add what is in nuxt.config.js
Maybe someone has come across a similar one?
If necessary, I will throw off the archive with example files.