debug test is grayed out in maven projects; debug test method not offered

In ant projects, right-click on a unit test file allowed to select debug-test. Debug test is now grayed out.

This morning I experienced a different behavior, that is, debug-test was possible, and even nicer, in the unit test output window, one can select debug specific method, which made me very happy. It cannot get this behavior back, not with java 8 nor with 11 or 12.