.scroll-down-link

try f.e.:

#top .scroll-down-link {
  height: 50px;
  width: 50px;
  bottom: 50px;
  background-color: rgba(255,255,255,0.3);
  border: 1px solid var(--enfold-socket-color-border);
  backdrop-filter: blur(4px);
  border-radius: 10px;
  /*** animation: none; ***/
}
#top .scroll-down-link.avia-svg-icon svg:first-child {
  height: 50px;
}

#top .scroll-down-link:hover {
  background-color: rgba(255,255,255,0.8);
}

#top .scroll-down-link svg path {
  fill: var(--enfold-main-color-primary);
}

if you do not like the animation – just get rid of the outcommenting /*** ***/

ok – you are right that on that icon the down-open-mini is used ! – you can change it by code snippet inside your child-theme functions.php:

function avia_replace_default_icons($icons){
 $icons['svg__scrolldown'] =  array( 'font' =>'svg_entypo-fontello', 'icon' => 'down-open');
 return $icons;
}
add_filter('avf_default_icons','avia_replace_default_icons', 10, 1);

you find those settings including the filter in init-base-data.php
there you see that the scrolldown icon is correlated with the down-open-mini svg.

charmap can be found in: charmap-svg.php

Isn’t it just a question of size? Wouldn’t specifying the width/height alone lead to the same result?
PS: in your case you are already use the svg icons. if someone uses the font-icons the snippet will be different –
and correlation is on default by:
'scrolldown' => array( 'font' => 'entypo-fontello', 'icon' => 'ue877' ),

this burger menu is not a font icon or a svg icon. These are simple containers with a given width and height.
The top and the bottom lines are pseudo-containers (before and after).

try in quick css: see next post for better solution ;)

btw. i do not see if you have set this rule yourself ( merged styles ):

@media only screen and (min-width: 485px) and (max-width: 1023px) {
  .html_av-submenu-hidden .av-submenu-indicator {
    margin-right: 175px;
    opacity: 100% !important;
    font-weight: bold !important;
  }
}

the margin-right value causes the icon to be overlaid with the text.

are these icons – enfold mangaged icons?
Or do they belong to your carousel plugin or instagram plugin ;)

ok – but even if you like to replace those icons:

.carousel-slider.arrows-outside .owl-nav svg {
  display: none
}

.carousel-slider.arrows-outside .owl-nav .owl-prev:before,
.carousel-slider.arrows-outside .owl-nav .owl-next:before {
  font-family: 'entypo-fontello';
  font-size: 52px;
}

.carousel-slider.arrows-outside .owl-nav .owl-next:before {
  content: "\E875";
}

.carousel-slider.arrows-outside .owl-nav .owl-prev:before {
  content: "\E874";
}

now the other ones …

on google ratings:

.ti-next:before,
.ti-prev:before {
  display: none !important;
}
.ti-next:after,
.ti-prev:after {
  display: flex;
  position: absolute;
  justify-content: center;
  align-content: center;
  align-items: center;
  width: 100%;
  height: 100%;
  border-radius: 100%;
  transition: all 200ms ease-out;
  font-size: 24px;
  font-family: "entypo-fontello";
  color: var(--enfold-header-color-color);
}

.ti-prev:after {
  content: "\E874" !important;
}
.ti-next:after {
  content: "\E875" !important;
}

.ti-prev:hover:after,
.ti-next:hover:after{
  color: #FFF !important;
  background-color: var(--enfold-header-color-color);
}

first remove this from your css

.ti-prev:hover::after, 
.ti-next:hover::after {
  color: #FFF !important;
  background-color: var(--enfold-header-color-color);
}

then:

#top .ti-widget .ti-controls .ti-next,
#top .ti-widget .ti-controls .ti-next:after,
#top .ti-widget .ti-controls .ti-prev:after,
#top .ti-widget .ti-controls .ti-prev {
  background: none !important;
  border: none !important;
  outline: none !important;
}

#top .ti-widget .ti-controls .ti-next {
  right: -10px;
}

#top .ti-widget .ti-controls .ti-prev {
  left: -10px;
}

First – a screenshot would be nice to have. Many misunderstandings could have been avoided beforehand if I had known more precisely what needed to be changed.

Next: i’m participant as you are, so if there is a message on private content field – i could not see it.

Thank goodness for DeepL — I did take French as my third subject in high school, but that was a good 40 years ago ;)

#top .ti-widget .ti-controls .ti-next,
#top .ti-widget .ti-controls .ti-next:after,
#top .ti-widget .ti-controls .ti-prev:after,
#top .ti-widget .ti-controls .ti-prev {
  background: none !important;
  border: none !important;
  outline: none !important;
}

#top .ti-widget .ti-controls .ti-next {
  right: -20px;
}

#top .ti-widget .ti-controls .ti-prev {
  left: -20px;
}

#top .ti-widget .ti-controls > div:after {
  font-size: 52px;
  color: #ebebeb;
}

#top .ti-widget .ti-controls .ti-prev:hover:after,
#top .ti-widget .ti-controls .ti-next:hover:after {
  color: #2c1175 !important;
}

maybe you have allready included some of those rules.