Coming back

We had a small infestation from around Oct- Feb and we got completely rid of them using advion and gentrol point source. We didn’t see any sign of anything for 13 weeks and then randomly saw an adult one we thought came in from a gift bag on a restaurant floor. Then saw nothing for 6 weeks then randomly saw two adults in one day during the day. Then a week later saw a nymph on the floor. All the recent sightings have been during the day and barely moving. I still have point source through out the house and advion here and there ever since the original problem in the winter. We are a single family home in NC. Could this be a new infestation starting up? I have kept things spotless from living through it the first time. Can they travel from a neighbors house maybe 50 yards away? I just don’t know what’s going on and why this could be happening again.