Attach (recommended) or Link to PDF file here:
https://s3.eu-west-1.amazonaws.com/scai-dev.website.com/tmp/8ab8b56a-fa91-11eb-8d74-0242ac110004.pdf

Hi,
Please see an incorrect canvas rendering for the following document - page 9 specifically. It reproduces on https://mozilla.github.io/pdf.js/web/viewer.html (tried with Chrome). Other pages in this document look pretty much the same but the problem is on page 9 only.

Original screenshot:
![image](https://user-images.githubusercontent.com/23075641/129066656-7bb2fb56-2b88-4f40-8e67-b95bdeb9e521.png)


PDF JS:

![image](https://user-images.githubusercontent.com/23075641/129066734-56503a5c-413c-49c1-9e1c-470da3a642ed.png)

for (j = 0; j < thisChunkHeight; j++) {
        const srcDiff = srcLength - srcPos;
        let k = 0;
        const kEnd = srcDiff > fullSrcDiff ? width : srcDiff * 8 - 7;
        const kEndUnrolled = kEnd & ~7;
        let mask = 0;
        let srcByte = 0;
        for (; k < kEndUnrolled; k += 8) {
          srcByte = src[srcPos++];
          dest32[destPos++] = srcByte & 128 ? white : black;
          dest32[destPos++] = srcByte & 64 ? white : black;
          dest32[destPos++] = srcByte & 32 ? white : black;
          dest32[destPos++] = srcByte & 16 ? white : black;
          dest32[destPos++] = srcByte & 8 ? white : black;
          dest32[destPos++] = srcByte & 4 ? white : black;
          dest32[destPos++] = srcByte & 2 ? white : black;
          dest32[destPos++] = srcByte & 1 ? white : black;
        }
        for (; k < kEnd; k++) {
          if (mask === 0) {
            srcByte = src[srcPos++];
            mask = 128;
          }
          dest32[destPos++] = srcByte & mask ? white : black;
          mask >>= 1;
        }
      }
      
      while (destPos < dest32DataLength) {
        dest32[destPos++] = 0;