Yandex search engine issuing a site after gluing?

Question

Search Engine Optimization

Hello!
Such a story, for a very long time the site was in the first position for the request " flower delivery Tyumen ", initially it was glued with its own kind, but recently they fell apart and the site began to gradually lose positions.
We noticed this, glued it again , but this procedure did not give a result .
We started digging and realized that the site takes a long time to load on computers (~6 seconds for a full load, ~12+ seconds on smartphones, respectively), we cleaned it up (removed unnecessary scripts, optimized photos), it brought resultsin the form of a site flickering to 2~3 positions , but this lasted for about a week , then it again dropped to 6~8 positions .
The whole question is what else can be done or what is wrong with the site, for what reasons it cannot break into the first position, in which it has been sitting for a year? We are talking about the site flowerstyumen72.rf

Answer 1

what else can you do

Fix JS errors, for example, at the same time, the slider on the site will start working. Including js and css files in your comments, but they forgot about this code. And not everything depends on your site alone, the topic is commercial, competitors are most often on the alert.
Install an SSL certificate, it will not be superfluous.

var slider = new MasterSlider();
      slider.setup('masterslider' , {
           width:800,    // slider standard width
           //height:350,   // slider standard height
           space:5,
       speed:10,
      view:'fade',
      swipe:true,
      autoplay:true,
      loop:true,
      autoHeight:true,
      layout:'fillwidth',
      overPause:false,
      centerControls:false,
      fullwidth:true


           // more slider options goes here...
           // check slider options section in documentation for more options.
      });
      // adds Arrows navigation control to the slider.
      slider.control('arrows');