The else will only happen if all of the If part is false. What I suspect is happening is that the light being on is forcing the Lum sensor to be >9 so the If part isn't firing when motion is active and the light is on.
I would use a nested if:
If motion is active then
Cancel delayed actions
If Lum is ... and time is ....
Turn light on
turn-light off after delay.
The two end-if's are VERY important to have here.
If fact, when motion goes active again, it is going to schedule another turn off after delay because you've fallen into the Else Bucket. That's why I would also use an Else-If motion is inactive to be safe.