This seems somewhat similar to  another thread here (Direct-To in out to FMC on Mac causes 0.3 fps). I noted this a week ago when entering a flight into the FMC, where there was a delay between clicking an FMC key and the data appearing (this may be the way that the real thing works, my one experience ion with a Mac so I assume it's related to that). The delay after clicking the FMC keys seemed to get worse,  After departure, I twice increased cruise altitude in the FMC (using VNAV).  This