Attach (recommended) or Link to PDF file here:
[FormDB2_fr.pdf](https://github.com/mozilla/pdf.js/files/7352426/FormDB2_fr.pdf)

Configuration:
- Web browser and its version: Firefox nightly
- Operating system and its version: linux debian

Steps to reproduce the problem:
1. Open the pdf
2. The image on the top of each pages is missing 

What is the expected behavior? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/137465500-e8788893-f33d-4532-871d-43b464fa85f4.png)

What went wrong? (add screenshot)
![image](https://user-images.githubusercontent.com/5641725/137465363-f2b35fe4-6776-45e9-b9e4-ccef6d9ad670.png)

return getAvailableSpace(this);
  }
  [$isSplittable]() {
    
    
    const parent = this[$getSubformParent]();
    if (!parent[$isSplittable]()) {
      return false;
    }
    if (this[$extra]._isSplittable !== undefined) {
      return this[$extra]._isSplittable;
    }
    if (this.layout === "position" || this.layout.includes("row")) {
      this[$extra]._isSplittable = false;
      return false;
    }
    if (this.keep && this.keep.intact !== "none") {
      this[$extra]._isSplittable = false;
      return false;
    }
    if (
      parent.layout &&
      parent.layout.endsWith("-tb") &&
      parent[$extra].numberInLine !== 0
    ) {