background-attachment: fixed; causes jittery parallax scroll in Safari

Anyone know of a workaround? Scrolling in Chrome, and even in the dev window is lovely, but when live in Safari only is a mess. Complicating things is I've added a static background effect for some index images, sample below:

.collection-type-index #building-block {
  background-image: url("https://static1.squarespace.com/static/5d668c3fb154060001bbf0ba/t/5dea9ae54fc5135240ef736c/1575656167172/3a.jpg");
  background-position: center;
  background-size: cover;
  background-attachment: fixed;
  background-repeat: no-repeat;
}

Turning "fixed" to any other attribute resolves the scrolling, but need a static image. Help?

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