Interested pax.
At slower speeds the volume and mass of air swept by the wing in unit time is reduced. To maintain 1g you need to generate a fixed rate of change of momentum and with less mass to deflect you must induce a higher downward speed change to the air.
With flaps deployed speed needed to maintain 1g will be reduced so at first sight would expect higher circulation again but the wing has changed and isn't uniform along the span. The outboard section is unchanged but without flaps you couldn't maintain 1g. So the lift generated by the outboard section is reduced compared to the clean configuration.
Hope this didn't annoy......