If you re-import a service that already has some test cases present, it may that these older test cases will be marked as outdated (means "coming from an older service version"). That depends on test meta data having changed or not.

Solution: Create New Test Cases

To get rid of the outdated test cases, you have to create new ones (based on the newly imported test case template) and adapt the new ones to match the outdated.
Then, delete the outdated test cases.

Solution: Manually Edit Test Case Files

To get rid of the hint to outdated test cases, you can manually edit each test case file. The test cases reside in the testcases folder of your Builder project.
Set flag outdated to false. The test case will appear as normal in the UI, but its definitions may by outdated nevertheless.