I've tried something similar with our internal wallboards, and have seen similar problems over time. I would double-check your base URL just to be sure there's not any problem there, but I suspect you'll need something like the JIRA wallboard plugin to make this work:
That should give you a predictable URL for its servlet and if you make a dashboard with only one column and gadget, the effect should be similar to putting a single gadget in an iframe.
Hi Atlassian community, My name is Max and I work on the product integration team at Atlassian. I am pleased to announce the early access program for the Jira Cloud add-in for Outlook. This add-in...
Connect with like-minded Atlassian users at free events near you!Find an event
Connect with like-minded Atlassian users at free events near you!
Unfortunately there are no Community Events near you at the moment.Host an event
You're one step closer to meeting fellow Atlassian users at your local event. Learn more about Community Events