Issue Summary

When using the bottom arrows to easily navigate from one attachment to another, the PDF images do not populate. To preview them properly, you must close the preview and then click the next attachment to open the preview again.

Steps to Reproduce

1. Open a card with Attachments (PDF ones).
2. Click on the attachment thumbnail to open the preview
3. Click on the bottom arrow to navigate to the other attachment preview.

Expected Results

You will navigate and see the PDF previews.

Actual Results

The first attachment preview open just fine; when you navigate to the next ones, no preview is displayed.

Getting the same behaviour in several browsers and incognito window.
That problem seems to be related to PDF previews only. Testing with images (like jpg/gif) it works fine.

Workaround

You need to close and click on the thumbnail again to see the preview.