If I'm using the 8.14 version of Optaplanner, not considering the option to move to a later version. Is there a way for me to implement problem change(real-time planning) using the solver instance created from solverManager.solveAndlisten() not the solver.solve()?
No, in 8.14 it's not possible to do problem fact changes on the SolverManager.
Either upgrade to 8.17 or use the workaround suggested in this answer: How to implement a problemFactChange while using optaplanner-spring-boot-starter?.
The workaround injects SolverFactory, builds a Solver instance and uses solver.solve().