This is how I solved that problem, too! Nothing turns on without motion for me, and nothing turns off based on lux alone. You didn't really say how you have your automations set up (just lux?) or why this is a problem, so you might get more specific ideas if you share more about that. In my case, I actually added mode on top of this with mode partially controlled by lux (the rest by sunrise/sunset and time). Lights only turn on based on motion in specific modes, except in dark interior rooms where they turn on all the time (except sometimes during "night mode," which for me is sleep).
Otherwise, if you're already using a rule and have a specific threshold set up, adding a "deadband" would be one way to avoid this problem. For example,
IF (Lux < 500) THEN
ELSE-IF (Lux > 700) THEN
So, nothing happens if it quickly changes from one value to another near your threshold (or now two thresholds).