Hello Jake,

Thanks for reaching out to us.

This is happening since there are two sliders configured, one is for the "standard" page and the other is for the "pop up". You can try applying this custom CSS code and it should fix the issue 

@media only screen and (max-width: 548px) {
  .amelia-v2-booking.am-dialog-el .el-dialog {
    margin-top: 0px !important;
  }
  .amelia-v2-booking #amelia-container .am-dialog-el__main-container {
    max-height: calc(100vh - 68px) !important;
  }
}

Custom code needs to be applied to the page where the booking form is. Depending on what you're using (Gutenberg blocks, or some page builder), adding the CSS or JS can be done in a few different ways. 

If you need help with adding custom CSS to the page, please take a look at this article.

Let me know if it works.