SVG Circle not animated in Edge

Question

The below svg animates perfectly in all browsers but Edge (surprise!).

<svg width="80" height="24" viewBox="0 0 120 30" xmlns="http://www.w3.org/2000/svg" fill="#555">
    <circle cx="15" cy="15" r="15">
        <animate attributeName="r" from="15" to="15"
                 begin="0s" dur="0.8s"
                 values="15;9;15" calcMode="linear"
                 repeatCount="indefinite" />
        <animate attributeName="fill-opacity" from="1" to="1"
                 begin="0s" dur="0.8s"
                 values="1;.5;1" calcMode="linear"
                 repeatCount="indefinite" />
    </circle>

</svg>

I tried adding px as units but no luck.

Thanks for your tips!

Answer 1

After reading the comments and answers I decided to go for clear CSS animation, instead of SVG. I grabbed the code from https://projects.lukehaas.me/css-loaders/ and my "solution" looks like this:

<style>
.loader,
.loader:before,
.loader:after {
  border-radius: 50%;
  width: 2.2em;
  height: 2.2em;
  -webkit-animation-fill-mode: both;
  animation-fill-mode: both;
  -webkit-animation: load7 1.3s infinite ease-in-out;
  animation: load7 1.3s infinite ease-in-out;
}
.loader {
  color: #888;
  font-size: 10px;
  margin: 80px auto;
  position: relative;
  text-indent: -9999em;
  -webkit-transform: translateZ(0);
  -ms-transform: translateZ(0);
  transform: translateZ(0);
  -webkit-animation-delay: -0.16s;
  animation-delay: -0.16s;
}
.loader:before,
.loader:after {
  content: '';
  position: absolute;
  top: 0;
}
.loader:before {
  left: -3.5em;
  -webkit-animation-delay: -0.32s;
  animation-delay: -0.32s;
}
.loader:after {
  left: 3.5em;
}
@-webkit-keyframes load7 {
  0%,
  80%,
  100% {
    box-shadow: 0 2.2em 0 -1.3em;
  }
  40% {
    box-shadow: 0 2.2em 0 0;
  }
}
@keyframes load7 {
  0%,
  80%,
  100% {
    box-shadow: 0 2.2em 0 -1.3em;
  }
  40% {
    box-shadow: 0 2.2em 0 0;
  }
}
</style>

<div class="loader">Loading...</div>