There has been a number KBs made available since the release of the update 370. Take a look these and apply the relevant fixes if you have the issues mentioned occurring in your environment. There are also a few FYI type KBs which I have not included here. For a full list visit the K2 customer portal.
KB000375 – Hotfix: Event Instances Report in the Process Overview Report shows events that belong to another activity. More

