Hi Alex,
I see. Thanks for clarifying. This is quite problematic for us, I had no idea that was how this was set up. When I was reading the documentation, I was under the impression that the grade passback would not happen until the student had clicked the link. Reading here: https://webwork.maa.org/wiki/LTI_Authentication_(for_WeBWorK_2.18_or_newer) it specifies that "Students must click on a link corresponding to an assignment at least once for grade pass back to work." But it seems you are saying that is not the case. And that if ONE student clicks the link it passes grades back for ALL students?!?
Is there no workaround for this? Is there a way to re-set it so that 'no one' has clicked the link, even an instructor? So that way we don't have to live with an entire gradebook filled with zeros right from the start of the semester?