I have a branching email trigger (i.e., if eligible to continue send email A; if ineligible, send email B) at the end of a survey that was working perfectly for many weeks, but has been failing over and over in the last three days.
I re-ran a bunch that had failed and they sent the second time. Then another one failed and retry attempts also failed.
Why might these be failing now when they weren’t before (and no changes were made to the workflow or the survey itself)?

