Hi @ctrav21 , 

Just a guess here, but since the earlier in the month invoice is the one showing up in 1-30, I wonder if that invoice was created before the terms were set? Piggybacking off of what @BigRedConsulting said about term changes not retroactively changing due dates on existing invoices... Does your Invoice template show the Due Date? and if so, does the due date on the invoice itself reflect the terms set?