Guest relationship is being deleted when a user created a call on lead or contact record, so call is not showing up in call sub-panel upon creation of call

Our users notified me that calls were "disappearing" from Sugar. On a hunch, I pulled a report showing any call that was not related to a contact or lead record (for reference, we directly work with individuals so we never relate calls to a company record)

Thousands of calls showed up from 2013-present day. 

I am looking for a workaround to ensure that the related to contact or lead is ALWAYS added as a guest to the call so the call will show up in the subpanel. I don't want a user to log an important phone call only to have it not save to the subpanel properly. 

Does anyone have a known fix for this issue?

Thank you!