I've seen the same pause using octoprint and attempting to connect to the rpi from a different computer than what's logged in, as an FYI to anyone thinking about going that approach. Onboard storage like an SD card will perform better, as the printer will read ahead and cache accordingly. From my experiences in bigger CNC equipment it's always best to have a dedicated controller with a bare minimum level of applications open/installed on the system if you're doing something like direct numeric control, as anything that diverts the resources can cause pauses like this. On windows 10 machines they're especially prone to randomly pulling resources, processing updates and indexing when they detect an idle in user activity. With machines like lathes and mills those pauses can scrap a part if you're trying to hold a half thousandth with a polished surface on a bore for a hydraulic cylinder, or leave witness marks on milled faces where the cutter paused during a spline cut and your spindle bearings are a few years old and have a little slop.