Attach (recommended) or Link to PDF file here:
[output.pdf](https://github.com/mozilla/pdf.js/files/6374987/output.pdf)

Configuration:
- Web browser and its version: Firefox 88.0
- Operating system and its version: macOS Big Sur 11.2.3 (20D91)
- PDF.js version: 2.8.243
- Is a browser extension: no/Firefox built-in

Steps to reproduce the problem:
1.  add Ink-Annotations to a pdf (i use https://github.com/highkite/pdfAnnotate, Annotations with appearance streams are shown correctly)
2. open output file in firefox

What is the expected behavior? 
The annotations should be visible.
![Bildschirmfoto 2021-04-26 um 09 15 48](https://user-images.githubusercontent.com/33630884/116043809-6a020f80-a670-11eb-973c-6f2df3dae532.png)

What went wrong? 
The annotations are added to the dom but invisible.
![Bildschirmfoto 2021-04-26 um 09 18 26](https://user-images.githubusercontent.com/33630884/116043867-7e460c80-a670-11eb-964d-0cc2c6dbfb61.png)

Tested successfull with FoxitReader, AcrobatReader, Chrome and Safari.
OPS,
  shadow,
  stringToPDFString,
  stringToUTF16BEString,
  unreachable,
  Util,
  warn,
} from "../shared/util.js";
import { collectActions, getInheritableProperty } from "./core_utils.js";
import {
  createDefaultAppearance,
  parseDefaultAppearance,
} from "./default_appearance.js";
import {
  Dict,
  isDict,
  isName,
  isRef,
  isStream,
  Name,
  RefSet,
} from "./primitives.js";
import { Catalog } from "./catalog.js";
import { ColorSpace } from "./colorspace.js";
import { FileSpec } from "./file_spec.js";
import { ObjectLoader } from "./object_loader.js";
import { OperatorList } from "./operator_list.js";
import { StringStream } from "./stream.js";
import { writeDict } from "./writer.js";
class AnnotationFactory {