I didn’t notice this in 6.3.0, so looks to have started in 6.3.3.
For my data-driven testing, I’m using external Excel files. Some of my data in the Excel files have single quotes in them. When Katalon populates those fields with the single quote, it’s surrounding the data in the field with a single quote at the beginning and the end. So
My field’s data is now ‘My field’s data’