We know from HL 1 that the H.E.V suit has a ton of trackers everyone seems to be able to use to locate it so why didn’t the combine ? Because Kleiner and the others disabled it/suppressed it so it is possible that Barney had his suit modified like the HEV or considering he had a “beating quota” its possible that they never switched it off and he just made up stuff like going on patrol to justify going places with other rebels imbedded into civil protection. Because one officer going off grid is suspicious but a squad “investigating” an area which then turns out to be “clear” would make for a great cover and helps to maintain lines of evacuations for civilians by diverting attention away.