Invasion of the Dinosaurs - S11-E2
Visible crew/equipment: In episode 4, when the Doctor is in the Whomobile, a dark cylindrical object passes in front of the camera in the foreground. It's not something of the Doctor's, as his hands are inside the vehicle.
The Monster of Peladon - S11-E4
Visible crew/equipment: When Azaxyr is setting his ambush for the miners in episode six, a studio light can be seen through a gap in the wall.
Answer: TARDISes are generally available for properly authorised use on Gallifrey; they're not usually assigned to a particular Timelord on a long-term basis. The Doctor stole his when he left his homeworld.
Tailkinker ★