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 input was delayed similar to the above the first time, then the second time I got the "spinning wheel" on the Mac, which after a while disappeared and I got the 0.3 fps (which makes the pull down menus almost impossible to use).
Like most people I have installed many addons, so I did a fresh install of XPX, installed FlyWithLua and RTH, and the IXEG B733 only. I did no FMC input, and the frame rate was around 26fps. I engaged the AP, then clicked ALT HLD on the MCP, which appeared to be non-responsive. I then clicked it again, and instant 0.3 fps. This lasted foar about 5 minutes then it came back to normal 25-26 fps.
My Mac is a 2014 "5k" model, 32GB RAM, 4GB vRAM, and an i7 quad core. I was running the B733 at 1080p resolution. I have a screenshot of the fps counter if ot would help.
Any help most appreciated. I get to "fly" XPX (my only sim) only an hour or two a week.
Thanks, Bruce.