But after the opening date (or after the student first clicks on the assignment?), the seeds change to something like 998, 998, 998, 998, ..., for every problem on the same assignment.
The strange part (to me) was that this same seed appeared on TWO different assignments which opened on the same day.
It would be helpful to understand what webwork is doing behind the scenes. For example, is it likely that if I take a problem from an assignment and put that same problem on a gateway quiz, will a student have the SAME SEED in both cases?
My short answer is "I don't think this should happen." I just tested it on my system, creating a set with two problems, assigned to me. The seeds for the two problems start as 258 and 2944, and don't change. Unassigning and reassigning it to myself, the seeds change to other values, but again don't change thereafter.
Is this for a normal homework assignment? Does it happen for all students? Which problems are you using in the assignment?
It's a normal homework assignment and it happens for all students. Not sure what you mean by "which problems" are in the assignments -- these are problems we've written, and this behavior happens for all assignments in all seven courses using webwork.
When the sets are newly assigned, the seeds (for a two-problem set) would be something like you say -- 258 and 2944. But as soon as the set opens, they will change for student #1 to be something like 35 and 35. I suspect that unassigning and reassigning would lead to a similar behavior but for new seeds initially, and then new (repeated) seeds afterward.
I only saw one situation where a student had identical (repeated) seeds for two assignments, and these were assignments which opened at the same time.
Sound like a database problem?
We're running 2.4.9.
Sorry for the posting -- but thanks for letting me know that it's not a webwork phenomenon. Now to look more closely at our scripts...