You may want to review existing assignments settings and the view on the batch dates updating page--the pattern of empty Assign To is pretty easy to notice in that view. If it isn't happening to you now, I would love to know why. We have hit an impasse with this one.
We had been using that method for the entire SY23-24 and first half of the SY24-25 year, but around mid-March this year, each time a new attempt was made on the source assignment, a new Assign To appeared. We would populate that empty date field, but as soon as someone else attempts the source assignment, yet another Assign To is created.
After many rounds with support, they determined it was expected behavior and referenced a line from the guides page on Conditional assignments:
"As conditional items are released to students, individual due dates for items are not applied. To add a due date to conditional items, wait until all students have completed the source assignment and then add a due date to the conditional item."
This had not been the behavior before circa March 12, 2025, but I have to acknowledge that the above note appears to have been under those Notes for a long time. Also, the note and support say to let everyone complete the source assignment before populating dates. We are asynchronous with a policy that students can work ahead, on time, or catch up without penalty. Letting the dates sit empty could last for weeks or even a month or more for us.
I could never get an answer to why we had not, in over a year and half of using the same method, we had not encountered this behavior before. We tested this method exhaustively before the fall of 2023. It behaved fine all of 2023-2024 and from fall of 2024 through mid March.
Again, I do suggest you check carefully. It is happening with perfect consistency for us now (regardless of assignment type). I have tested extensively again to see if I can get the behavior to ever not repeat. So far, every time we populate a date on a triggered assign to, the next student to enter the path gets a new blank assign to.
Our teachers are almost ready to rebel against our use of Mastery Paths on this one.