Custom Picker displays None as a result in the Pie chart gadget. This issue is replicable using Jira 8.20.1 and ScriptRunner 6.57^. It seems to occur after the fix for: SRJIRA-5652. In ScriptRunner versions 6.56 and earlier, the custom picker returns the results accordingly in the gadget.

Likely related to: SRJIRA-6549

Steps to Reproduce

1. Create a custom picker with the attached script file.
2. Use that custom picker in some issues in Jira.
3. Create a filter to gather all those issues having that custom picker.
4. Open the dashboard and add a Pie chart gadget.
5. Choose the custom picker field in the statistic type.
6. Result displayed:
   

Expected Behaviour

Custom picker displaying the result accordingly using Pie chart gadget:

Actual Behaviour

Custom picker displaying None as a result in the Pie chart gadget:

Additional Info

• Screenshot configuration