Attach (recommended) or Link to PDF file [here:] Can't see how to attach a pdf here, but it is simple to create. Add a form object textbox to a pdf and make sure the option for "Multiline" is true.

Steps to reproduce the problem:
1.  Open a document with a Textbox that is set to Multiline.
2. Attempt to hit the Enter key to go to a new line.

What is the expected behavior? The cursor goes to a new line.

What went wrong? It does not go to a new line.

Link to a viewer: It can be reproduced on mozilla.github.io/pdf.js

I corrected the issue by altering the pdf.js file like this
element.addEventListener("keydown", event => { 
[...]
--} else if (event.key === "Enter") {
++ } else if (event.key === "Enter" && !this.data.multiLine) {

Our initial testing is coming through clean, and hopefully something like this code can be committed to the project in the future.

this.data.rect[3] - this.data.rect[1] - BORDER_SIZE
      );
      computedFontSize = Math.min(
        fontSize,
        roundToOneDecimal(height / LINE_FACTOR)
      );
    }
    style.fontSize = `calc(${computedFontSize}px * var(--scale-factor))`;
    style.color = Util.makeHexColor(fontColor[0], fontColor[1], fontColor[2]);
    if (this.data.textAlignment !== null) {
      style.textAlign = TEXT_ALIGNMENT[this.data.textAlignment];
    }
  }
  _setRequired(element, isRequired) {
    if (isRequired) {
      element.setAttribute("required", true);
    } else {
      element.removeAttribute("required");
    }
    element.setAttribute("aria-required", isRequired);
  }
}
class TextWidgetAnnotationElement extends WidgetAnnotationElement {
  constructor(parameters) {
    const isRenderable =
      parameters.renderForms ||
      (!parameters.data.hasAppearance && !!parameters.data.fieldValue);
    super(parameters, { isRenderable });
  }
  setPropertyOnSiblings(base, key, value, keyInStorage) {