Currently the Jira resource provides polyfills for the find and findIndex methods based on an older version as documented on MDN. This has since been updated to ensure configurable and writable are both set to true however this change to the standard has not been applied to the polyfills provided in the Jira resource which means libraries built based on MDN as an industry standard are breaking in Jira server.
How have others worked around this problem, there’s an existing issue that’s been raised a while back for this, which I’ve added more details to today in the hopes the problem can be resolved.