subsequent Confluence images not showing correctly in JIRA activity stream

Summary

When you attach any additional images after the first edit in Confluence page, all the latest images you attached will be appear as broken in JIRA activity stream

Environment

• JIRA 7.3.4
• Confluence 6.1.1

Steps to Reproduce

1. Setup application link between JIRA and Confluence via 2-legged OAuth
2. Create a test page in Confluence and attach 3 images
3. Refresh JIRA dashboard, all 3 images from the Confluence pages showing correctly in the JIRA activity stream
4. Edit the existing test page in Confluence, add additional images, then save it

Expected Results

The latest attached images shows correctly in JIRA activity stream

Actual Results

The latest attached images appears to be broken in JIRA activity stream

Notes

When you mouse over the broken image, the URL seems to consist of double forward slash which is invalid, example:

http://localhost:8090/confluence//download/attachments/1015834/2014-bmw-m3-f30.png?version=1&modificationDate=1492074144633&api=v2

Workaround

Attach all the required images when you first create the Confluence page.