Yes, this happens with Part Select set to all (or any other setting). It's not that the difference isn't audible. When this happens, there is no sound at all. It's like the loading of the wavetable and sample just failed and nothing at all is loaded. When it happens the 'trigger LED flashes while loading' flashing is also much longer then normally (I mentioned 2 seconds above, but during my last jam, I noticed it was more like 4 seconds).
Btw, I was just jamming, and after a while the module just totally crashed: the trigger LED was on continuously and there was a medium-high pitched beep coming out of the module. Totally unresponsive afterwards, only a rack off/on solved it. This the second time this happened now.