Well, I played with it a little bit. Had same problem with another static page. Managed to fix it by copying whole markup from another page(include template name file) and then put old markup back by three parts and renamed template file to new name. And voila – same old markup and plugin works.
Weirdo behavior… At least it works now. I’ve tried aswell to purge all cache/disabling plugin but with no luck. Haven’t any of caching plugins installed, though before had installed w3 cache and velocity minify. Velocity for a week or so worked with Litespeed Cache(minifying and combining options were disabled in Litespeed), but as I find that Velocity crashes markup with Litespeed I’ve deleted it and enabled minifying/combining settings in Litespeed Cache.