We have a weird issue that when we try to proof a delivery on our Staging instance, and select "Enable proof sending" in the Approvals, the target population drops to zero when there are non-zero amount of targets. There are no targets being removed by typologies (I removed all typologies), duplicates or blacklisting. If we uncheck "Enable proof sending" in the Approvals, the target population returns to normal This doesn't happen with exactly the same campaign and delivery on our production instance.
This happens with most deliveries, but not all for some reason. Anyone seen this or know how to fix it?