This article will explain to you how to fix the blank line issue in the custom JQL gadget.
Issue Description
When performing field aggregation in JQL Custom Charts, it's important to note that if a specific field is blank for certain issues, a corresponding blank line will appear in the JQL chart, indicating a count of 0 for that particular category.
Reason
The field count shows 0 with the blank line because the null value is not equal to another null value, that’s why it does not get grouped in, when the count of the category is calculated.