As I understand the site is created on the EAP. There are several different theories as to why this might happen. (Note that the problem currently exists).
1) due to Sint. errors in scripts prorvyomsya further loading of styles and scripts
Error in console (tested in Lyss)
Plain text document does not contain a Declaration of character encoding. If the document contains characters outside the US-ASCII range, in some configurations of the browser, the document will be displayed garbled text. The character encoding of the file needs to be declared in the transfer Protocol or file needs to use the indicator byte order mark (BOM) as a signature encoding.
TypeError: a.ui is undefined
SyntaxError: "string literal contains an unescaped line break
2) Eliminate the potential conflict of plugins and themes.
3) Eliminate the problem of plugins keshirovaniya and website optimization. (You have some plug-in uses technologies pagespeed to optimize the code.)
4) Check the correctness of connection of scripts and styles (to correctly connect scripts and styles in functions.php)
5) Check the correctness of the order of connection of scripts and styles. Since you have the theme on bootstrap, the first bootstrap is to be connected, and then style.css you Have it in reverse.
6) something in the CSS file of the theme do not mind comments with the topic name, version, etc.