I think this is the CSS from our plugin that controls it:

.search-filter-scroll-loading {
  display: block;
  margin: 10px;
  margin-top: 20px;
  height: 30px;
  width: 30px;
  animation: search-filter-loader-rotate 0.7s infinite linear;
  border: 5px solid rgba(0, 0, 0, 0.15);
  border-right-color: rgba(0, 0, 0, 0.6);
  border-radius: 50%;
}

That is the css that our plugin uses to place the icon. If you could just repeat here the page I would see it on (it is buried in another thread I suspect)? I can then take a look to see if it can be moved.

So, I had to experiment a bit. By way of an explanation for others, in the browser inspector, I manually added this HTML inside the body tag, at the end of the page:

<div class="search-filter-scroll-loading"></div>

This is what our javascript does when the infinite scroll is loading. Then it was a case of finding the CSS, which I had already shown was this:

.search-filter-scroll-loading {
    display: block;
    margin: 20px 10px 10px;
    height: 30px;
    width: 30px;
    animation: search-filter-loader-rotate .7s infinite linear;
    border: 5px solid rgba(0,0,0,.15);
        border-right-color: rgba(0, 0, 0, 0.15);
    border-right-color: rgba(0,0,0,.6);
    border-radius: 50%;
}

Then I had to find a way to move the icon. Making it position: absolute; means that it will always appear towards the top of the page, and so out of view when the page has been scrolled down. Making it position: relative is OK, but I do not know where exactly on the page our javascript places it. So, the extra CSS might be:

.search-filter-scroll-loading {
  z-index: 99999999;
  left: 50%;
  top: 100%;
  position: relative;
}

This puts it in the middle of the page horizontally, but you will have to play with these numbers (left and top).