can't connect custom. css

Hello!
I'm using a template HelixUltimate.
I made my own custom style sheet — custom.css
In the template settings, in the "Before </head>" block, I connect a custom. css file. And save the changes in the template settings. However, the style sheet does not connect! How can I fix this?

https://imgur.com/a/BEDmvYU

http://terrasvs48.temp.swtest.ru/