This one solved it for me. It doesn’t stick, it still shrinks, but it doesn’t change transparency

@media only screen and (max-width: 767px) {
  #top #wrap_all .header_color {
    background: transparent;
    position: absolute!important;
  }

  .responsive #top .header_color.av_alternate_logo_active.av_header_transparency .logo a > img {
    opacity: 0 !important;
  }

  .responsive #top .header_color.av_header_transparency .logo img.alternate {
    display: block !important;
  }

  .responsive #top .header_color #header_meta {
      -webkit-transition: none;
      transition: none;
      background: transparent;
  }

  .responsive #top .header_color .header_bg {
      opacity: 0;
      filter: alpha(opacity=0);
  }

  .responsive #top .header_color #header_main {
      border: none;
  }
}