Ben Affleck was finally able to leave his Brentwood home and chill in the neighborhood with his son and a new dog … after a dramatic start to the new year with wildfire scares — and subsequent security issues in the area.

It seems Ben upped his personal security in the form of a four-legged pal … and took the K-9 out for a relaxing stroll with his kiddo — and men from Trident Elite Protection Dogs — on Friday.

The outing marks a strong contrast for BA who initially fled his mansion … then had to deal with one security issue after another just outside his front door in the wake of the massive, deadly Palisades fire.

Days after he was forced to evacuate his place for Jennifer Garner‘s … the FBI paid a visit at Ben’s home — ’cause agents were in the area investigating an incident in which a private drone collided with a firefighting aircraft, damaging it. Our sources said Ben wasn’t the target of the probe.

Then earlier this week … Ben was spotted having a tense conversation with police outside his property, sounding like he’s upset with the amount of questions he’s been peppered with while coming and going from his neighborhood by private security.

Don’t get it twisted — Ben didn’t seem to be pissed at actual officers, but annoyed by the private security team.

And to cap off the week of irritants … on Thursday, a massive sand-colored military Humvee was parked outside his home with a man in uniform — the National Guard was deployed last week to help amid the Pacific Palisades wildfire.

To be fair … Ben’s house is located near the edge of the evacuation zone, so the area is being constantly patrolled.