Forum Discussion
Implementing the TSP with DFJ subtour elimination constraints
To learn how callbacks work in Xpress, based on the answer by Daniel Junglas in this question: https://community.fico.com/s/question/0D54W00008P73MsSAJ/lazy-cut-callback-in-java, I've been experiment...
This might be obvious, but did you check that your cut is actually (significantly) violated?
I suggest to check the cut directly on the varIndices/coefficients arrays that you pass to addCuts() and on the solution vector you get from getLpSol().