Jira doesn't show attachment file name and extension on certain issue in new UI

Summary

When users are trying to download attachments of issues while using the "New Jira Issue View", Jira will download the file in its "original", without extension. The issue is inconsistent, as it does not occur on all issues but on certain issues created

Steps to Reproduce

Not always reproducible

• Create an issue, go to the comment and upload an image
• Open an issue while using the "New Jira Issue View" (link);
• Try to download an attachment from the attachment field.

Expected Results

• The name and the extension of the file is retained.

Actual Results

• Jira will show the file in its "original" name and remove its extension.

Workaround(s)

Switch back to the old UI from the Personal Settings by doing the following:

1. Click on your avatar picture (bottom left corner of the screen) and select "Personal Settings", or just navigate to: https://XXXXXX.atlassian.net/secure/ViewPersonalSettings.jspa
2. In the "Jira Labs" section, click to disable the New Jira issue view