<iframe> background tag makes my <grid> x axis scroll bar disappear but not the grid

Question

So I have a website, I am building and I have borrowed an iframe from another source. When I apply it to the background of my HTML, it removes a horizontal scrollbar from my horizontal scrolling grid. I feel like this is something to do with lower level programming which I don't really have time to delve into but if there's an easy fix I'm all ears.

HTML

<h1 class="titlec">Riley's Home Page</h1>
<div class="ticker-scroll-grid">
  <div class="card card-tall card-wide">card1</div>
  <div class="card card-tall card-wide">card2</div>
  <div class="card card-tall card-wide">card3</div>
  <div class="card card-tall card-wide">card4</div>
  <div class="card card-tall card-wide">card4</div>
  <div class="card card-tall card-wide">card5</div>
  <div class="card card-tall card-wide">card6</div>
  <div class="card card-tall card-wide">card7</div>
  <div class="card card-tall card-wide">card8</div>
  <div class="card card-tall card-wide">card9</div>
</div>

If I comment out the iframe the scrollbar re-appears.

CSS

:root {
  font-size: 16px;
  font-family: 'Open Sans';
  --text-primary: #b6b6b6;
  --text-secondary: #ececec;
  --bg-primary: #23232e;
  --bg-secondary: #141418;
  --transition-speed: 600ms;
  margin: 0;
  padding: 0;
}

html,
body {
  color: black;
  background-color: rgb(80, 10, 10);
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  height: 100vh;
  /* width: 100%; */
  display: flex;
  flex-direction: column;
}

.fluid_block {
  width: 100%;
  height: 100vh;
  background: grey;
  position: fixed;
  margin: 0;
  /* z-index: 0; */
}

.ifrm_fluid {
  width: 100%;
  height: 100%;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
}

body::-webkit-scrollbar {
  width: 0.8rem;
}

body::-webkit-scrollbar-track {
  background: #1e1e24;
}

body::-webkit-scrollbar-thumb {
  background: #6649b8;
}

body,
main {
  /* margin-left: 5rem; */
  margin: 0rem 0rem 0rem 0rem;
  position: relative;
  width: 100%;
  height: 100vh;
  box-sizing: border-box;
}

.ticker-scroll-grid {
  display: grid;
  gap: 1.5rem;
  margin-top: 1rem;
  margin-bottom: 1rem;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  grid-auto-flow: column;
  grid-auto-columns: minmax(240px, 1fr);
  grid-auto-rows: 60px;
  overflow-x: auto;
  scrollbar-width: thin;
  scrollbar-width: thin;
  padding-left: 0.6rem;
  padding-right: 0.6rem;
  width: 99%;
  box-sizing: border-box;
}

.gricontainer {
  margin: 10px;
  width: 100%;
}

.ticker-scroll-grid::-webkit-scrollbar {
  height: 0.4rem;
}

.ticker-scroll-grid::-webkit-scrollbar-track {
  background: rgb(14, 204, 14);
  margin-left: 1em;
  margin-right: 1em;
  border-radius: 8px;
  /* opacity: 100%; */
}

.ticker-scroll-grid::-webkit-scrollbar-thumb {
  background: red;
  border-radius: 8px;
}

.card {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  background: #353535;
  font-size: 3rem;
  color: #fff;
  box-shadow: rgba(3, 8, 20, 0.1) 0px 0.15rem 0.5rem, rgba(2, 8, 20, 0.1) 0px 0.075rem 0.175rem;
  height: 100%;
  width: 100%;
  border-radius: 10px;
  transition: all 250ms;
  overflow: hidden;
  text-align: center;
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  position: relative;
  /* object-fit: fill; */
}

.card:hover {
  box-shadow: rgba(2, 8, 20, 0.1) 0px 0.35em 1.175em, rgba(2, 8, 20, 0.08) 0px 0.175em 0.5em;
  transform: translateY(-3px) scale(1.03);
}