I'm betting its a combination of the age of accounts increased to another milestone and that maybe a late or two dropped off.

Also did you actually check your reports? Some CA (very few, but some) do delete once you pay - even without asking....maybe one of them deleted once you paid....

Current: Eq- 624 Ex - 631 (lender pulled) TU - 661 (lender pulled)
Goal 700+ across all three