I'm facing one issue as below, please let me know if you any idea.

we have 3 stages in case type and there are two more parallel flows introduced in stage 2.

The existing flow in stage 2 is intact. these 3 parallel flows in stage 2 are getting triggered based on when rule added in the case type "Start process when".

The inflight cases which are already in stage 2 with flow-1 are going into pzstageproblems when user advanced case with newly added changes in stage-2.

For now i have added changestage explicitly at end of stage 2 in flow-1 for inflight cases which is working fine.
but any reason for this why the change stage is not happening from stage-2 to stage-3 for inflight cases with new changes in stage-2?