From the DMN 1.5 spec [1], a Decision Table with a single output column shouldn't have a name.

8 Decision Table
8.1 Introduction
...
• A set of outputs (one or more). A single output has no name, only a value. Two or more outputs are called
output components. Each output component SHALL be named. Each output (component) SHALL specify an
output entry for each rule. The specification

Currently, a single output column has a name, and it's possible to edit it using the Decision Table properties panel. In the following image, the column name is "Output-1".

This cause a validation error, as the JIT Executor uses the strict mode:

ILLEGAL_USE_OF_NAME: Decision table with single output on node 'New Decision' should not have output name

[1] https://www.omg.org/spec/DMN/1.5/Beta1/PDF