There is a third option besides tidal lock and night/day cycle.
Some moons in the outer Solar System have Chaotic Rotation[1]. These bodies don't have a fixed rotation axis or period.
There could still be such a Moon orbiting a planet in the habitable zone, or even a small planet in a belt like structure orbiting close to a red dwarf.
I wonder what lifeforms could evolve when the amount of light/energy received is unpredictable and varies constantly?