Hello Jose,

Thanks for reaching out to us.

It's not a bug, this issue occurs because of the two sliders for each booking form. By default, your website has a slider option, but when you open an event, there is another slider.

You can try using this custom CSS code

@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 us know if it works.