The only snip that should be executing in the learning phase is the learning snip, and if you don’t have any learning connections, it shouldn’t be doing much of anything. However, you could try turning it off anyway, just to see if it helps. The easiest way is probably to edit nengo_loihi/hardware/snips/nengo_learn.c.template so that the guard function returns 0 instead of 1. That should stop the snip from running at all.