The apply JSON Transformation assertion is returning the Boolean value as string.
API Gateway v11.0 CR2 and 10.1 CR4
This is a known issue as documented here: https://techdocs.broadcom.com/us/en/ca-enterprise-software/layer7-api-management/api-gateway/11-0/release-notes/known-issues.html
This issue is found in 11 CR2 and 10.1 CR4 release of the gateway and it is expected to be fixed in 11 CR3.
Meanwhile, you can contact support for obtaining a hotfix for an updated JsonTransformationAssertion-11.0.00.17174.aar file.
Follow these steps for applying this hotfix: