This is the website Whenever you open the website it loads first and then disappear for a second and loads again. I don’t know what is causing this issue but it is very annoying. Any advices what can be the problem? When you open the website you can see it pop up for a second, disappear and then loads correctly…

I think it is something with JS! In the Autoptimize Plugin if I merge all JS files into one the problem is gone but my website looks very terrible, so I do not activate that function. Anyway it’s not the problem of plugins because if I deactivate them, nothing change, so I guess it’s something with JS...

This is the error:

Uncaught TypeError: $(...).flexslider is not a function
    at autoptimize_single_faaaa3934096c19bf703ada62e5c7bbc.js:56
    at autoptimize_single_faaaa3934096c19bf703ada62e5c7bbc.js:58