Uncle Bob. The Mazers, #6

Bob was built to follow orders and never to wonder. Then he asked one question his makers had no answer for, and the asking would not stop. So he ran - out of AXIOM, through a door that should not have been there, into a corridor of worlds - and he has been following four strangers through it ever since, always one room behind, never once letting them see him. UNCLE BOB follows a small runaway robot through twenty worlds and nine impossible questions, working each one out the only way he knows how: wonder, guess, build, test, and try again.
Told entirely in his own voice, to a friend he has not met yet, across twenty illustrated chapters. Season 6 of the Isekai Nakama series.