Timeline updated based on start date previous to today's current date - General Caster & linked duration

I have General Caster, and I am trying to update projects that have already started (making the start date earlier than today’s current date), and the timeline will not reflect anything earlier than the current date. For instance, I am using a start date of April 3, with a duration of 14 days, and the timeline is reflection Sept 20 - Oct 3

I have the timeline column linked with the duration, and am using the following automations & formulas:

When [column changes], perform formula and cast to [column]

When StartDate Changes:
CONCATENATE(TEXT(DATEVALUE({task’s Start Date}), “YYYY-MM-DD”), “+”, TEXT(DATEVALUE({task’s Start Date}) + {task’s Duration}-1, “YYYY-MM-DD”))
And cast result to Timeline

When Duration Changes:
CONCATENATE(TEXT(DATEVALUE({task’s Start Date}), “YYYY-MM-DD”), “+”, TEXT(DATEVALUE({task’s Start Date}) + {task’s Duration}-1, “YYYY-MM-DD”))
And cast result to Timeline

When Timeline changes:
TEXT(DATEVALUE(LEFT({item’s Timeline}, 10)), “YYYY-MM-DD”)
And cast result to StartDate

I am getting looping errors or “unexpected error” and I can’t seem to figure out what is not working. Any suggestions?