Failing to render the jira macro results from time to time

Comment from Michael Hamann :

> Anything that's async is stored in a cache for a short time. And when that cache is full or doesn't store the item because it thinks (based on some approximation) that it's not accessed frequently, you'll get those errors.
> To me the proper fix is not to use a cache for storing async items but a data structure that has more reliable storage.