"Related to" Disappears (Case Activity)

I have updated to SuiteCRM 8. I am having an issue when I add an activity under a case. The edit view shows the related to (Customer) when I am adding an activity. However when I click save, the relationship disappears and is not visible in the history subpanel. I have to go to Tasks edit the activity there, add the relationship then it appears. Does anyone know why this is happening? I am in dire need to go live, but this is an issue I am having thats preventing me from doing so.