Less activities placed after deactivating constraints

[pg788]

Is it possible that the software places less number of activities after some constraints are relaxed/removed/deactivated?
I would expect that relaxing or ignoring constraints should allow more flexibility and hence easier placement of activities. Does the opposite indicate a bug in my data?

[Liviu Lalescu]

There are cases in which this is possible. Because additional constraints may help FET.

Think about locking a timetable. It is solved instantly.

[Liviu Lalescu]

Also deactivating/removing/lowering constraints may change the initial order of the activities when placing them on the timetable, so that if there is a difficulty it may come earlier.

[pg788]

I see, thanks.