Hi,
it might depend on your trigger. For example, if your trigger is "When record created" and you add record by hand, automation will run on empty record before you fill any data. In that case workaround will be - to change it to "When record matches condition". Condition should be "non empty" for fields you interested. You could also add next field, or end with some non-typed field (like single select or check box)
For example, if you set 'First Name not empty" and "Last Name not empty", and input "John", "Doe", Automation will run at "John", "D".
Check "Run history" and "Field Values" for last run to be sure.