Ok, I have not found any issue on my demo system. Send some screenshots if it can be reproduced. The simulate recalculates calculated KF's based on values changed manually in the workbook such as capacity utilization % if you manually change the capacity available. The unconstrained planning in the simulation drop down actually runs the algorithm for supply heuristic which needs to be saved if desired for the changes to take affect permanently.
In the advanced section of the ribbon, the supply planning drop down kicks of a batch job which automatically saves the output but you need to reopen or refresh the workbook to see the outcome of the plan.