He did because he THOUGHT he was still dreaming.
He had a temporary mental break from hallucinating his brother’s memory. Thats why he was low-energy and melancholy during the final scene UNTIL he saw Judge Judy was real, at which point he became joyful.
Every scene with Earn, Al, and Van was real. THEY are Darius’s “Totem” as it were. The scenes with Darius by himself are all hallucinations in which he’s connected in some way to his brother.
Going into a Pharmacy to get his brother’s medication, something he most likely did for his ailing brother when he was alive
Meeting up with London, who reminds him of time when he was younger and wilder (and when his brother was alive)
Meeting up with his brother and having “comfort food” together (Jollof Rice)
These are all in some way connected to the brother.
The Popeyes was another hint that they were in reality. Remember Darius saw the Popeyes commercial after the first Judge Judy episode played in the opening scene, he got them Popeyes in the car because subconsciously thats the last thing he remembers before going to the tank