Hi Prassana,
The standard recommendation for automated testing is Mendix Application Test Suite (ATS). ATS contains the recording and UI unit testing features you're looking for, plus it integrates directly with the Mendix project management portal, and it has API hooks for your CI/CD pipeline.
If you'd still like to use Katalon, we can try to help you debug the issue here. Can you share the script for the step that is failing? My assumption is that the Selenium target/selector didn't script itself correctly in the recorder.