The Calving Distribution Issues window is available on the desktop version of Herdly. You can get to it by going to Tools > Calving Distribution Issues? or from the Dashboard window by clicking the Dashboard button and choosing Calving Distribution Issues? from the menu.
If the calving distribution chart in the Dashboard doesn't look correct, it may be that some of your ranch data isn't correct. It can be tricky to figure out why sometimes. This window explains how Herdly figures out when the first cycle of a calving season begins in general. It also shows exactly which logic was triggered on your ranch for a particular year. Armed with this information you'll be able to fix the issue.