Hey @ScottB,
this has to do with the way UI Kit works. Instead of running in the browser, the whole state is sent via GraphQL, the new UI state is computed in a Lambda function on Atlassian servers and the whole state is sent back to the browser to be displayed.
If you are dealing with too ‘large’ data-sets the whole app crashes and you can’t contain the error. For us, this meant reducing the amount of data we handle as state i.e. setting hard-coded limits for the number of Issues we retrieve and reducing the number of fields as much as possible.
Here you can find some people who are facing the same problem.
This most likely will be solved with UI Kit 2, since the state is handled in the browser then.
Alternatively you could also use Custom UI.